1-5- MacLean 2014 & van Horik 2018 Flashcards
(126 cards)
1
Q
How was cognitive evolution been explained at the proximate level?
A
Cognitive evolution has been explained at the proxi- mate level by shifts in absolute and relative brain volume
2
Q
How has cognitive evolution been explained at the ultimate level?
A
and at the ultimate level by differences in social and dietary complexity.
3
Q
What has previous research relied on?
A
previous research has largely relied on various measures of brain size as proxies for cognitive abilities
4
Q
How many individuals were involved?
A
567
5
Q
How many species were used
A
36
6
Q
What did absolute brain volume predict?
A
abso- lute brain volume best predicted performance across species and accounted for considerably more variance than brain volume con- trolling for body mass.
7
Q
What type of measurement predicted ability across species?
A
abso- lute brain volume best predicted performance across species and accounted for considerably more variance than brain volume con- trolling for body mass.
8
Q
Within primates, ____ ____ but not _____ _____ _____ was a strong predictor of species differences in self-control.
A
Within primates, dietary breadth but not social group size was a strong predictor of species differences in self-control.
9
Q
With little data on how cognition varies across species, previous research has largely relied on what?
A
previous research has largely relied on proxies for cognition (e.g., brain size) or metaanalyses when testing hypotheses about cognitive evolution
10
Q
Across species, differences in ______ (not _____) brain volume best predicted performance on these tasks.
A
Across species, differences in absolute (not relative) brain volume best predicted performance on these tasks.
11
Q
At the _____ level, both absolute (77, 99–107) and relative brain size (108–112) have been proposed as mechanisms supporting cognitive evolution.
A
At the proximate level, both absolute (77, 99–107) and relative brain size (108–112) have been proposed as mechanisms supporting cognitive evolution.
12
Q
Evolutionary increases in brain size (both ab- solute and relative) and cortical reorganization are hallmarks of the ______ ______ and are believed to index commensurate changes in _____ _____
A
Evolutionary increases in brain size (both ab- solute and relative) and cortical reorganization are hallmarks of the human lineage and are believed to index commensurate changes in cognitive abilities
13
Q
What does the cortical reorganisation hypothesis suggest?
A
The cortical reorganization hypothesis suggests that se- lection for absolutely larger brains—and concomitant cortical reorganization—was the predominant mechanism supporting cog- nitive evolution
14
Q
What does the encephalisation hypothesis suggest?
A
the encephali- zation hypothesis argues that an increase in brain volume relative to body size was of primary importance
15
Q
What does the social intelligence hypothesis propose?
A
The social intelligence hypothesis proposes that in- creased social complexity (frequently indexed by social group size) was the major selective pressure in primate cognitive evolution
16
Q
What evidence supports the social intelligence hypothesis?
A
studies showing a positive correlation between a species’ typical group size and the neocortex ratio
17
Q
What does the foraging hypothesis suggest?
A
The foraging hypothesis posits that dietary complexity, indexed by field reports of dietary breadth and reliance on fruit (a spatiotemporally distributed resource), was the primary driver of primate cognitive evolution
18
Q
What evidence supports the foraging hypothesis?
A
supported by studies linking diet quality and brain size in primates (79, 81, 86, 142, 155), and experimental studies documenting species differences in cog- nition that relate to feeding ecology
19
Q
What does a comparison of the relative contributions of the different proximate and ultimate explanations require?
A
a comparison of the relative contributions of the different proximate and ultimate explanations requires
(i) a cognitive dataset covering a large number of species tested using comparable exper- imental procedures;
(ii) cognitive tasks that allow valid measure- ment across a range of species with differing morphology, percep- tion, and temperament;
(iii) a representative sample within each species to obtain accurate estimates of species-typical cognition;
(iv) phylogenetic comparative methods appropriate for testing evolu- tionary hypotheses; and
v) unprecedented collaboration to collect these data from populations of animals around the world
20
Q
How do animals show self control?
A
animals re- quire self-control when avoiding feeding or mating in view of a higher-ranking individual, sharing food with kin, or searching for food in a new area rather than a previously rewarding for- aging site.
21
Q
What is self control related to in sparrows?
A
In song sparrows, a study using one of the tasks reported here found a correlation between self-control and song repertoire size, a predictor of fitness in this species
22
Q
What is self control related to in humans?
A
humans, self-control has been linked to health, economic, social, and academic achievement, and is known to be heritable
23
Q
What was self control related to in primates
A
In primates, performance on a series of nonsocial self-control control tasks was related to variability in social systems (174), illustrating the potential link between these skills and socio- ecolog
24
Q
How many species and individuals did the A not B task?
A
27 species, n = 344
25
What was the A not B task?
In the A-not-B task (27 species, n = 344), subjects were first familiarized with finding food in one location (container A) for three consecutive trials. In the test trial, sub- jects initially saw the food hidden in the same location (container A), but then moved to a new location (container B) before they were allowed to search
26
How many animals/species did the cylinder task?
32 species, n = 439
27
What was the cylinder task
In the cylinder task (32 species, n = 439), subjects were first familiarized with finding a piece of food hidden inside an opaque cylinder. In the fol- lowing 10 test trials, a transparent cylinder was substituted for the opaque cylinder. To successfully retrieve the food, subjects needed to inhibit the impulse to reach for the food directly (bumping into the cylinder) in favor of the detour response they had used during the familiarization phase
28
Thus, the test trials in both tasks required subjects to inhibit _______________ (searching in the previously rewarded location or reaching directly for the visible food), but the nature of the correct response _____________
Thus, the test trials in both tasks required subjects to inhibit a prepotent motor response (searching in the previously rewarded location or reaching directly for the visible food), but the nature of the correct response varied between tasks.
29
Across species and accounting for phylogeny, performance on the two tasks was what?
Across species and accounting for phylogeny, performance on the two tasks was strongly correlated (r = 0.53, n = 23, P < 0.01).
30
Phylogenetic analyses revealed that scores were more _______ among ______ related species, with the maximum likelihood estimate of λ, a measure of _______ _____, significantly greater than ____ in most cases
Phylogenetic analyses revealed that scores were more similar among closely related species, with the maximum likelihood estimate of λ, a measure of phylogenetic signal, significantly greater than zero in most cases
31
How did they control for the nonindependence of species level data?
Tocontrolforthe nonindependence of species level data, we used phylogenetic generalized least squares (PGLS) to test the association between performance on the cognitive tasks and the explanatory variables associated with each hypothesis.
32
What were the neuroanatomical predictors?
Our neuroanatomical predictors included measures of absolute brain volume [endocranial volume (ECV)], residual brain volume [residuals from a phylogenetic regression of ECV predicted by body mass (ECV residuals)], and Jerrison’s (108) encephalization quotient (EQ)
33
Across species, absolute brain volume (measured as ECV) was a _____ predictor of performance (Fig. 2 and Table 2), sup- porting the predictions of the _____ ________ hypothesis.
Across species, absolute brain volume (measured as ECV) was a robust predictor of performance (Fig. 2 and Table 2), sup- porting the predictions of the cortical reorganization hypothesis.
34
ECV covaried ______ with performance on the _______ task and the _______ ____ and explained substantial variance in performance
ECV covaried positively with performance on the cylinder task and the composite score and explained substantial variance in performance
35
How was the association between EVC and the A not B task?
This association was much weaker for the A-not-B task, reflecting that the largest- brained species (Asian elephant) had the lowest score on this measure
36
Which species had the lowest score for the A not B task?
Elephant
37
The same A not B & EVC analysis excluding the elephant yielded WHAT?
The same analysis excluding the elephant yielded a strong and significant positive association between ECV and scores on the A-not-B task
38
Across the entire sample, _____ brain volume was far less predictive than ____ brain volume:
Across the entire sample, residual brain volume was far less predictive than absolute brain volume
39
How much variance did residual brain volume explain in composite scores?
3%
40
Residual brisk volume was a significant predictor of performance in how many tasks?
was a significant predictor of performance in only one of the tasks
41
EQ was positively related to _______ scores across species (β=0.28,t21 =3.23,P<0.01,λ=0,r2 =0.33)butagain explained far less variance than _____ ____ ____.
EQ was positively related to composite scores across species (β=0.28,t21 =3.23,P<0.01,λ=0,r2 =0.33)butagain explained far less variance than absolute brain volume.
42
Why did the redo the analyses with just primates?
the best-represented taxonomic group in our dataset
43
Within primates, what did absolute brain volume show?
Within primates, absolute brain volume was the best predictor of performance across tasks and explained substantial variation across species
44
How was the analyses on primates different to all species ?
In contrast to the analysis across all species, residual brain volume was predictive of performance on both tasks within primates, although it explained much less variance than absolute brain volume
45
Within primates the analysis using EQ as a predictor of composite scores was similar to that using ____ residuals
of composite scores was similar to that using ECV residuals
46
What were the analyses like when they only used non primates ?
Within the nonprimate species, ECV was again the best predictor of self-control, and was significantly and positively associated with composite scores and scores on the cylinder task, but not the A-not-B task
47
In the non-primate analyses, what did removing the elephant do?
Removing the Asian elephant from the analysis of the A-not-B task did not change this result
48
What was the effect of EQ and residual brain volume in the non-primate analyses?
Residual brain volume was not a significant predictor of any of these measures (Table 2), and EQ was unrelated to com- posite scores
49
How did they measure social complexity?
As a measure of social complexity, we tested the hypothesis that social group size, which covaries with the neo- cortex ratio in anthropoid primates (129), would predict per- formance in the self-control tasks.
50
What social aspects did they measure for group size?
To explore multiple variants of this hypothesis, we investigated both species-typical pop- ulation group size and foraging group size as predictor variables.
51
How did group size effect task performance?
Neither measure of group size was associated with task perfor- mance (Fig. 3, Table 2, and Table S7), echoing findings using observational data on behavioral flexibility
52
How did they test the foraging hypothesis
We tested the foraging hypotheses by examining whether the degree of frugi- vory (percent fruit in diet) or dietary breadth (number of dietary categories reported to have been consumed by each species) (92) predicts performance.
53
How did diet effect performance?
The percent of fruit in a species’ diet was not a significant predictor of any of the cognitive measures (Fig. 3, Table 2, and Table S7). However, dietary breadth covaried strongly with our measures of self-control
54
What did a multiple regression show?
This model explained 82% of variance in perfor-
mance between species with significant and positive coefficients
for both absolute ECV and dietary breadth, controlling for the
effects of one another
55
Thus, while 11 2
correlated with one another (t = 3.04, P < 0.01, λ = 0, r = 0.32), both ____ ____ and _____ _____ account for unique components of variance in primate cognition, together explain- ing the majority of interspecific variation on these tasks.
Thus, while 11 2
correlated with one another (t = 3.04, P < 0.01, λ = 0, r = 0.32), both brain volume and dietary complexity account for unique components of variance in primate cognition, together explain- ing the majority of interspecific variation on these tasks.
56
What were the r values for dietary breadth and EVC
In this model the independent effect for dietary breadth (r2 = 0.45) was comparable to that for ECV (r2 = 0.49).
57
Controlling for observational research effort, our experimental measures covaried positively with what?
Controlling for observational research effort, our experimental measures covaried positively with reports of in- novation, extractive foraging, tool use, social learning, and tac- tical deception in primates
58
Our experimental measure also covaried with a “____ ____” factor, ___ (92), derived from these observational measures
Our experimental measure also covaried with a “general intelligence” factor, gs (92), derived from these observational measures
59
Maximum likelihood reconstruction of ancestral states implies gradual cognitive evolution in the lineage leading to apes, with a convergence between apes and capuchin monkeys (Fig. 4 and SI Text). Thus, what?
Maximum likelihood reconstruction of ancestral states implies gradual cognitive evolution in the lineage leading to apes, with a convergence between apes and capuchin monkeys (Fig. 4 and SI Text). Thus, in addition to statistical inferences about ancestral species, this model reveals branches in the phylogeny associated with rapid evolutionary change, convergence and divergence, and the historical contexts in which these events occurred.
60
_______________\was only weakly related, and ____________ was unrelated, to variance in self- control.
residual brain volume was only weakly related, and social group size was unrelated, to variance in self- control.
61
The weaker relationship with residual brain volume and lack of relationship with social group size is particularly surprising given what?
The weaker relationship with residual brain volume and lack of relationship with social group size is particularly surprising given the common use of relative brain volume as a proxy for cognition and historical emphasis on increases in social group size as a likely driver of primate cognitive evolution
62
Why might absolutely larger brains confer greater cognitive advantages than relatively larger brains?
One possibility is that as brains get absolutely larger, the total number of neurons increases, and brains tend to become more modularized, perhaps facilitating the evolution of new cognitive networks
63
the best performing species in our sample were predominantly who?
the best performing species in our sample were predominantly anthropoid primates, species that have evolved unique prefrontal areas that are thought to provide a cognitive advantage in foraging decisions that rely on executive function
64
Nonetheless, other species without these neuroanatomical specializations (eg unique prefrontal areas) also performed well, raising the possibility of what?
the possibility that the cognitive skills required for success in these tasks may be subserved by diverse but functionally similar neural mechanisms across species
65
What is an ultimate explanation for dietary breadth explaining performance?
One plausible ultimate explanation is that individuals with the most cognitive flexibility may be most likely to explore and exploit new dietary resources or methods of food acquisition, which would be especially im- portant in times of scarcity.
A second possibility is that dietary breadth rep- resents an ecological constraint on brain evolution, rather than a selective pressure per se (116, 155, 184, 185). Accordingly, species with broad diets may be most capable of meeting the metabolic demands of growing and maintaining larger brains, with brain enlargement favored through a range of ecological selective pressures
66
it is likely that dietary breadth acts both as a ____ ____ and a _____ ____ of cognitive evolution
it is likely that dietary breadth acts both as a selective pressure and a metabolic facilitator of cognitive evolution
67
The relationship between self-control and absolute brain vol- ume is unlikely to be a nonadaptive byproduct of selection for increases in body size for several reasons
First, a comparison of models using only body mass or ECV as the predictor of com- posite scores yielded stronger support for the ECV model both in an analysis across all species [change in the Akaike informa- tion criterion (ΔAICc) = 0.77], and within primates
Second, the number of neurons in primate brains scales isometrically with brain size, indicating selection for constant neural density and neuron size, a scaling relationship that contrasts with other orders of animals
Third, ancestral state reconstructions indicate that both absolute and relative brain volume have increased over time in primates, whereas body mass has not (187).
Lastly, although not as predictive as absolute brain vol- ume, residual brain volume was a significant predictor of self- control in several of our analyses.
68
With the exception of ____ ____ we found no significant relationships between several socioecological variables and mea- sures of self-control.
With the exception of dietary breadth we found no significant relationships between several socioecological variables and mea- sures of self-control.
69
Why was the finding that most socioeconomic variables did not correlate with performance suprising?
These findings are especially surprising given that both the percentage of fruit in the diet and social group size correlate positively with neocortex ratio in anthropoid primates
70
These experimental measures will be particularly important given that even the most predictive neuroanatomical measures failed to account for more than __% of cognitive variance across species in this study.
These experimental measures will be particularly important given that even the most predictive neuroanatomical measures failed to account for more than 30% of cognitive variance across species in this study.
71
How did they measure cylinder success
Although subjects may have initially failed to perceive the transparent barrier on the first test trial, they had ample opportunity to adjust their behavior through visual, audi- tory, and tactile feedback across the 10 test trials.
For the cylinder task our dependent measure was the percentage of test trials that a subject per- formed the correct detour response, which was averaged across individuals within species to obtain species means.
72
Transparent Cylinder and Barrier tasks are used to purportedly assess what?
Transparent Cylinder and Barrier tasks are used to purportedly assess inhibitory control in a variety of animals
73
What did they record
We recorded the number of times subjects incorrectly attempted to access a reward through transparent barriers, and their latencies to solve each task.
74
We found little evidence that their performances were consistent across the two different ______________
We found little evidence that their performances were consistent across the two different Putative Inhibitory Control Tasks (PICTs)
75
Critically,____________of transpar- ent tasks, either Barrier or Cylinder, also improved subsequent inhibitory control performance on a novel task, suggesting that ______________
Critically, prior experience of transpar- ent tasks, either Barrier or Cylinder, also improved subsequent inhibitory control performance on a novel task, suggesting that they also learned the general properties of transparent obstacles.
76
Individual measures of _________, assayed in a third task, were positively related to their frequency of incorrect attempts to solve the transparent inhibitory control tasks.
Individual measures of persist- ence, assayed in a third task, were positively related to their frequency of incorrect attempts to solve the transparent inhibitory control tasks.
77
What had no influence on individual performance?
Neopho- bia, Sex and Body Condition had no influence on individual performance.
78
Contrary to previous studies of primates, pheasants with poor performance on PICTs had a _____________
Contrary to previous studies of primates, pheasants with poor performance on PICTs had a wider dietary breadth assayed using a free-choice task.
79
What sheds doubt on macleans findings
subsequent more detailed species-specific work has cast doubt on the interpretation of these findings (see [3]). Ravens (Corvus corax), New Caledonian crows (C. moneduloides) and Jackdaws (Corvus monedula) have recently demonstrated comparable performances to the apes from the MacLean et al. [19] study on the Cylinder task [5], and New Caledonian crows show improved performance on an A-not-B task if they were trained to attend to an exper- imenter’s hand movements [3], despite substantially smaller absolute brain sizes.
80
How do parrots cast doubt on macleans findings
parrots showed poor performances on A not B task, despite their relatively large brain size [4], and guppies (Poecilia reticulata) showed comparable performances to most of the birds and mammals reported in MacLean et al. [19] despite their much smaller brain size
81
Accordingly, a number of non-cognitive traits may contribute to differences in performances on cog- nitive tasks. What is an example of this?
For example, North Island robins (Petroica longipes) in poor Body Condition showed impaired performances on an inhibitory control task compared with those in good Body Condition [23]. Moreover, increasing arousal has been found to enhance inhibitory control per- formances in calm, but not excitable, dogs
82
What was the issue with Maclean using captive animals
Apes in cap- tivity, for example, may engage in a wide variety of cognitive tasks throughout their lifetime and are typically tested by humans, which interact with them behind transparent barriers [24]. Yet, sanctuary chimpanzees and bonobos have been found to outperform their zoo counterparts on an inhibitory control task
83
Why might glass be an issue?
Comparisons of inhibitory con- trol performance in domestic species, such as dogs [8], may also be confounded by different experiences with transparent barriers, such as glass windows and doors. Such experiences may explain why pet dogs outperformed shelter dogs on an A-not-B task, although no differences were found in the Cylinder task [11].
84
Pheasants are _____ and if artificial incubators are used, batches of individuals can be hatched __________________, to control for age effects.
Pheasants are precocial and if artificial incubators are used, batches of individuals can be hatched on the same day, to control for age effects.
85
Pheasants were presented with two different PICTs, a _____ task and a ______ task, but were divided into two groups so that they experienced these tasks in a _________ ____.
Pheasants were presented with two different PICTs, a Cylinder task and a Barrier task, but were divided into two groups so that they experienced these tasks in a counterbalanced order.
86
What did the pheasants have to do
For each task, birds were required to successfully navigate a pre-training apparatus, in which they learned to detour around an opaque apparatus to acquire a mealworm reward. Birds were then presented with an identical, but transparent, test apparatus in which they could similarly obtain a clearly visible mealworm.
87
If previous experience with transparent barriers influences subsequent performance on PICTs, what did they predict?
If previous experience with transparent barriers influences subsequent performance on PICTs, we predicted birds would show reduced latencies to solve, and make fewer incorrect attempts to acquire the reward on a second, albeit novel, task.
88
How did they do a dietary breadth task?
birds could sample a variety of familiar food items within a standardized time-frame
89
As motivational, non-cognitive traits have also been found to influence per- formances on cognitive tasks [21,22], what did they do?
As motivational, non-cognitive traits have also been found to influence per- formances on cognitive tasks [21,22], we also presented birds with another task to assess their ‘persistence’, in which attempts to acquire clearly visible, but inaccessible, mealworms placed under a Petri dish lid were recorded.
90
As Body Condition has been found to influence performances in PICTs in other birds [23], and differences in growth rates may also influence performances on tasks involving food rewards, what did they do?
As Body Condition has been found to influence performances in PICTs in other birds [23], and differences in growth rates may also influence performances on tasks involving food rewards, we also recorded the Sex and Body Condition of each bird.
91
The repeatability of each individual’s performance across the two different PICTs were also determined to assess what?
The repeatability of each individual’s performance across the two different PICTs were also determined to assess whether capacities for the same cognitive processes were accurately measured on each task.
92
How many pheasants were used ?
Two-hundred pheasant chicks were hatched in incubators, ran- domly assigned to groups of 50 in four replicated enclosures
93
How many birds participated in all trials?
Eighty-one birds participated in all trials
94
What was the basic procedure?
For each trial, subjects could acquire a freely avail- able mealworm that was positioned in front of the apparatus (Baseline Worm) and mealworms that were positioned inside the apparatus (Reward Worm). The presentation order of the Barrier and Cylinder tasks was counterbalanced across subjects.
95
What was the opaque training detour task?
Each bird initially received four trials on an opaque training apparatus, following MacLean [19]. Subjects were required to learn to detour around a barrier (Barrier task), or reach inside a cylinder (Cylinder task).
We recorded latencies (sec) from enter- ing the test chamber to when they acquired the Baseline Worm and Reward Worm, as well as the number of times each bird pecked at the apparatus.
A trial ended when the bird acquired the Reward Worm, or after 240 s if they failed to acquire the Reward Worm.
96
What was the transparent testing detour task?
Birds were presented with three trials on a transparent test apparatus the day after they completed their respective training trials.
Details of the Cylinder and Barrier apparatuses are presented in the electronic supplementary material.
Test trials were identical to the training trials, except that the apparatus was transparent and the Reward Worm was clearly visible.
To access the mealworms, birds had to place their head inside the opening of the pot in the Cylinder task, and detour around the barrier in the Barrier task.
Baseline and Reward Worm latencies and Pecks were recorded for each individual.
97
How was persistence measured?
Birds were presented with a transparent Petri dish (5 cm diameter), fastened horizontally to a white base (20 20 cm), that contained approximately 70 visible, but inaccessible, mealworms.
All birds were tested on the same day and experienced one trial in the morn- ing and one trial in the afternoon.
We recorded the number of Pecks that each individual directed towards the Petri dish as they attempted to acquire the mealworms for one minute
98
How was dietary breadth measured?
Before participating in this test, we placed an ad libitum supply of commercial parrot food, containing a variety (greater than 10) of different food items (i.e. seeds, dried fruits, chilli peppers, differ- ent coloured kibble) in each pen for 7 days.
During the testing session, 10 different food items were presented in a fixed array (see electronic supplementary material, figure S1).
We recorded how many different food items that each bird sampled within a single 2 min session.
99
How was sex and body condition measured?
At 10 weeks old, 2 days after testing had ceased, all subjects were sexed using visual cues and their mass was recorded using a spring balance scale (Slater Super Samsom – precision 5 g).
Tarsus length was also measured using a caliper (precision 0.1 mm) to determine Body Condition (mass/tarsus3).
100
Do transparent test apparatuses evoke prepotent
| responses?
Baseline Worm acquisition latencies did not differ between opaque and transparent apparatuses.
However, birds took longer to acquire the Reward Worm, and made more Pecks, on the transparent test apparatuses compared with the opaque training apparatuses
101
Do performances differ between tasks?
Baseline Worm acquisition latencies did not differ between the Barrier and Cylinder tasks, yet birds took longer to acquire the Reward Worm, and made more Pecks, on the Barrier task, compared with the Cylinder task
102
Do performances improve across trials?
Birds acquired the Baseline Worm and Reward Worm faster, and made fewer Pecks, as trials progressed
103
Does previous experience influence subsequent
| performance?
Birds that had previously experienced either the Cylinder or Barrier tasks were faster to acquire the Baseline Worm and Reward Worm, and made fewer Pecks on their first test trial of their second task
104
Are individual performances consistent across tasks?
Baseline Worm acquisition latencies were inversely related across tasks and there was no relationship between Reward Worm latencies or Pecks across the two tasks. Individuals showed no repeatability in their Baseline Worm acquisition latencies , however, this is a likely consequence of low variation in this response measure. Latencies to acquire the Reward Worm were moder- ately repeatable across tasks but repeatability of Pecks to the transparent apparatuses was low and non-significant
105
Is persistence and dietary breadth related
| to performance?
Baseline Worm and Reward Worm latencies were unrelated to Persistence or Dietary Breadth
How- ever, birds that made more Pecks on the transparent test apparatuses were also more persistent in pecking at the inac- cessible mealworms placed under a clear Petri dish lid, and had a wider Dietary Breadth
An indi- vidual’s performance in the persistence task was repeatable, suggesting that it reliably captured their persistence. Although birds made fewer Pecks on their second trial of the Persistence task, compared with their first trial their number of Pecks correlated posi- tively across trials and individuals showed high repeatability across trials different food items on the Dietary Breadth task.
106
Does Sex and Body Condition influence
| performance?
Sex and Body Condition had no influence on Baseline Worm latencies, Reward Worm latencies or number of Pecks
107
Pheasants showed inconsistent performances on two differ- ent, but functionally identical, tasks that purportedly assess capacities for inhibitory control. Performance on these tasks were instead explained by _____________
Pheasants showed inconsistent performances on two differ- ent, but functionally identical, tasks that purportedly assess capacities for inhibitory control. Performance on these tasks were instead explained by previous experience with transpar- ent barriers and other non-cognitive behavioural attributes, including greater persistence and a wider dietary breadth.
108
What fundamental implications are there?
First, that differences in individual experience must be con- trolled.
Second, that non-cognitive, motivational traits may confound performance on cognitive tasks.
Third, that the construct validity of different inhibitory control tasks is unclear and requires further investigation.
109
Performances differed between transparent and opaque apparatuses for both the Cylinder and Barrier tasks. These findings were not due to novelty, why?
Performances differed between transparent and opaque apparatuses for both the Cylinder and Barrier tasks. These findings were not due to novelty, as there were no differences in latencies to acquire a freely available Baseline Worm between transparent or opaque apparatuses
110
Birds took ____, and made more _______ _____, to acquire the food reward on the transparent, rather than opaque, appara- tuses.
Birds took longer, and made more incorrect attempts, to acquire the food reward on the transparent, rather than opaque, appara- tuses.
111
Like guppies [20], pheasants took longer, and made more errors, to solve the ____ task compared with the ____ task.
guppies [20], pheasants took longer, and made more errors, to solve the Barrier task compared with the Cylinder task.
112
Barrier task was not due to neophobia,why?
Barrier task was not due to neophobia, as their latencies to approach and acquire a freely available Baseline Worm did not differ between the two tasks.
113
As trials progressed on a given task, birds became ___, and made _____ ________ attempts to acquire the reward.
As trials progressed on a given task, birds became faster, and made fewer redundant attempts to acquire the reward.
114
Hence, birds learnt to inhibit their prepotent responses as they gained experience of each task. Consequently, what,
Hence, birds learnt to inhibit their prepotent responses as they gained experience of each task. Consequently, an indi- vidual’s performance on one trial is not independent of their performance on previous trials.
115
birds that had previously experienced a transparent appar- atus made fewer errors on a subsequent PICT compared with inexperienced individuals. However, by counterbalan- cing the presentation order of tasks, it also remains possible that birds’ performances improved on their second task as they were older.
Why were they not overly concerned about this?
there was only a 3 day interval between their first and second testing sessions we consider this an unlikely explanation. To control for possible age effects, future studies could incorporate a third group that experienced their first trial on a transparent apparatus at the same age as those birds that had previously experienced a transparent apparatus.
116
Indeed, pet dogs have been found to outperform shelter dogs on a similar detour task [11]. We might also expect species that are regularly tested on transparent apparatuses, or behind transparent barriers which separate experimenters from subjects, to show superior capacities for inhibitory control.
Such experience may explain what?
Indeed, pet dogs have been found to outperform shelter dogs on a similar detour task [11]. We might also expect species that are regularly tested on transparent apparatuses, or behind transparent barriers which separate experimenters from subjects, to show superior capacities for inhibitory control. Such experience may explain why primates, particularly the non-human great apes, initially outperformed corvids on inhibitory control tasks [19], but failed to do so when corvids received modified testing procedures [
117
Pheasants showed _____ _____ in their attempts to retrieve inaccessible mealworms across trials
Pheasants showed individual consistency in their attempts to retrieve inaccessible mealworms across trials
118
Yet, although pheasants generally made fewer Pecks on their second trial on the Persistence task, those birds that were more persistent also showed what?
Yet, although pheasants generally made fewer Pecks on their second trial on the Persistence task, those birds that were more persistent also showed inferior performances on the PICTs.
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In contrast to primates [19], however, these birds also appeared to have a wider dietary breadth, as indicated by the greater number of food items sampled in the Dietary Breadth task. It remains unclear about what?
It remains unclear why superior capacities for inhibitory control in pheasants should correspond with a nar- rower dietary breadth, whereas in primates a wide dietary breadth was a strong predictor of species differences in inhibitory control
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It is possible that in pheasants, indi- viduals that were highly motivated for food found it more difficult to inhibit prepotent attempts to acquire a visible mealworm. Why did they think this
Indeed, North Island robins in poor Body Condition had inferior inhibitory control on a Cylinder task than those birds in good Body Condition [23]. However, we found no evidence that either persistence or dietary breadth influenced latencies to acquire a freely available worm (Base- line Worm), or latencies to solve each task
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as males are larger than females [33], we might expect their faster growth rates to result in higher food motiv- ation. Yet what?
as males are larger than females [33], we might expect their faster growth rates to result in higher food motiv- ation. Yet performances on PICTs by pheasants were unrelated to Sex or Body Condition.
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We found little evidence that an individual’s performance was consistent across two similar PICTs suggesting what?
We found little evidence that an individual’s performance was consistent across two similar PICTs suggesting that Barrier tasks have a low construct validity and may not pro- vide a reliable assay of individual capacities for inhibitory control.
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We found no repeatability of inter-individual vari- ation in the _______ ___ _______ ______ (_____) to solve different PICTs. However, inter-individual variation in latencies to solve different PICTs were _______ _______.
We found no repeatability of inter-individual vari- ation in the number of incorrect attempts (Pecks) to solve different PICTs. However, inter-individual variation in latencies to solve different PICTs were moderately repeatable.
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the speed in which individuals solved each task were consistent, possibly due to what?
the speed in which individuals solved each task were consistent, possibly due to similarities in their inherent motivational state
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What are the implications of this study?
First, comparisons of inhibitory control performances, between individuals or species, may be con- founded by different experiences with transparent barriers.
Second, non-cognitive traits, such as persistence or dietary breadth, may contribute to individual differences in inhibi- tory control performance.
Finally, the mechanisms underlying cognitive performance on different inhibitory control tasks remains unclear and requires further investi- gation.
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Our findings highlight how non-cognitive traits can influence what?
Our findings highlight how non-cognitive traits can influence performance on tasks that are considered to assess particular cognitive capacities
