Biopsychology of emotions

Question 1

What is arousal?

Answer 1

Refers to a heightened state of physiological and psychological activation, marked by increased alertness and responsiveness to environmental stimuli.

An aspect of arousal is the “fight or flight” response, where the body prepares to confront or evade perceived threats by releasing stress hormones like adrenaline.

Different theories.

Question 2

What is the concept of emotion?

Answer 2

• subjective feelings.
• automatic
• rapid onset
• evolutionary survival.

Question 3

What did Breedlove and Watson (2018) say?

Answer 3

• Emotion applies to several different things, the word emotion, the word emotional and physiological changes accompanying emotions.
• Define emotion as: “a subjective mental state that is usually accompanied by distinctive behaviours as well as involuntary physiological changes” (p468).

Question 4

What are the key structures of the limbic system?

Answer 4

• Hippocampus
• Amygdala
• Thalamus
• Frontal cortex registers emotion

Question 5

Explain the limbic system’s explanation for emotion.

Answer 5

• Limbic system as an explanation of specific brain circuits of emotion.
• Emotion involves relatively primitive circuits.
• Conserved throughout evolution of mammals.
• Cognitive processes might involve other circuits (neocortex) and might function relatively independent of emotional circuits (MacLean, 1949, 1952, 1970).

Question 6

Give evidence for the limbic system’s role in emotion.

Answer 6

• Le Doux (1987, 1991) – Limbic system plays a role through interaction with systems outside.
• The limbic system theory is inadequate as an explanation of the specific brain circuits of emotion (LeDoux 2000).
• (LeDoux, 2012).
  *The limbic system theory attempted to explain all emotions within a single anatomical concept.
  *Contemporary researchers focus on tasks designed to study the brain systems of specific emotions.
• the brain theory approach (i.e., the hypothesis that discrete emotion categories consistently and specifically correspond to distinct brain regions)
• the psychological constructionist approach (i.e., the hypothesis that discrete emotion categories are
  constructed of more general brain networks, not specific to those categories).
• Meta-analysis found little evidence that discrete emotion categories can be consistently and specifically localised to distinct brain regions.
• evidence that is consistent with a psychological constructionist approach (Lindquist et al., 2012)
• Meta-analysis found evidence for the basic brain theory of emotions (Vytal and Hamann, 2010).

Question 7

What is the amygdala?

Answer 7

• Situated within the medial temporal lobe of the brain, serves as a pivotal structure in emotional processing and response modulation.
• Referred to as “the emotional brain” by LeDoux in 1998, the amygdala plays a crucial role in evaluating the significance of sensory stimuli and generating appropriate emotional responses.
• It is involved in coordinating hormonal and autonomic reactions to emotional stimuli, thereby influencing physiological arousal and behavioral responses.
• The amygdala operates unconsciously, rapidly processing incoming sensory information and triggering instinctual emotional reactions, while the cortex, responsible for conscious thought and reasoning, may process the same stimuli more slowly and deliberately.
• This “quick and dirty” route through the amygdala allows for rapid assessment of potential threats and immediate responses to danger, such as fear, even before conscious awareness of the situation.

*Fear responses are associated with the amygdala, as it detects and responds to cues associated with danger or threat, triggering fear-related behaviours and physiological changes to ensure survival in threatening situations.

Question 8

What are the substructures of the amygdala?

Answer 8

• Lateral Nucleus (LN)
• Basal Nucleus
• Central Nucleus (CN)

Question 9

What is the lateral nucleus?

Answer 9

• Receives sensory information from the neocortex, thalamus, and hippocampus.
• Projects to the basal and central nucleus of the amygdala.

Question 10

What is the basal nucleus?

Answer 10

information sent to the
ventromedial prefrontal cortex and central nucleus.

Question 11

What is the central nucleus?

Answer 11

Receives information from the basal and lateral nuclei.
Projects to many brain regions involved in emotional processes.

Question 12

Give evidence for the amygdala’s role in emotions.

Answer 12

MRI of different views of the brain and the amygdala:

• Damage reduces or abolishes a range of emotional behaviours.
• Lesions produce lack of fear response in monkeys (Amaral, 2003).
• Lesion studies have found impaired recognition of emotional facial expressions following bilateral amygdala damage, often for fear (Adolphs et al. 1995).
• Sometimes multiple negative emotions, including fear, anger, disgust, and sadness (Adolphs, et al. 1995, 1999)
• However not all with lesions are impaired (Adolphs, et al, 1999).
• Activated when viewing facial expressions of fear ( Hoffman et al., 2007).
• Activated for negative and positive emotions compared to neutral stimuli. (Costafreda et al., 2008).

Question 13

What can happen after amygdala damage?

Answer 13

• Abolition of emotional behaviours
• fear recognition in facial expressions and voice
• activated by emotional stimuli
• Psychopathy – reduced reaction to emotional stimuli
• Amygdala dysfunction, reduced volume, reduced response to negative words
• Emotional Memory

Question 14

How does amygdala activity vary in response to changes in emotional intensity and valence? Support your answer with evidence from studies showing amygdala responses to positive and negative stimuli, and discuss the implications of lateralized amygdala activity for emotional processing.

Answer 14

• The left and right amygdalae were sensitive to changes in emotional intensity.
• Activating more in response to stimuli with higher intensity.
• Positively valenced visual stimuli (Bonnett et al., 2015)
• Viewing blocks of negatively valenced baby faces evoked bilateral amygdala activity
• Viewing positively valenced ones resulted in left amygdala activity only (Baeken et al., 2009).

Question 15

What is the critical role of the prefrontal cortex, particularly the ventromedial prefrontal cortex (vmPFC), in emotional processing and regulation.

Answer 15

• Conscious emotional feelings
• Planned action
• Damage, reduced emotional recognition (Martins et al. 2012).
• Also reduces recognition of social cues (Martins et al.,2012).
• Sends outputs to many brain regions including the lateral hypothalamus and amygdala
• Receives information about the environment
• Perform a range of behaviours and physiological responses.
• Involved in inhibiting emotional responses in certain situations.

Question 16

Explain Phineas Gage accident.

Answer 16

In 1848, Gage, a railroad construction foreman, survived a severe accident in which a large iron rod was driven through his skull, damaging significant portions of his frontal lobes, including the ventromedial prefrontal cortex.

Question 17

What happen to Phineas Gage’s behaviour after accident?

Answer 17

Pior to the injury, he was described as responsible, reliable, and well-liked. However, after the accident, he became impulsive, irritable, and disinhibited, displaying poor decision-making and social judgment. His case demonstrated the crucial role of the vmPFC in personality, emotional regulation, and social behavior.

Question 18

How did Phineas Gage’s case contribute to our understanding of brain function localization, particularly in the ventromedial prefrontal cortex, and its broader implications for brain-behavior relationships?

Answer 18

Gage’s story became widely known because it provided evidence for the localization of function within the brain. By correlating Gage’s personality changes with the specific brain regions damaged by the accident, researchers were able to infer the functions of the vmPFC, such as inhibiting impulsive behavior, regulating emotions, and modulating social interactions. Gage’s case thus became a landmark in the study of brain-behavior relationships and laid the foundation for understanding the roles of different brain regions in cognition, emotion, and social behavior.

Question 19

Who did research on Phineas Gage?

Answer 19

Harlow, 1868

Question 20

Explain the studies that contribute to our understanding of the role of the ventromedial prefrontal cortex in emotional processing, and how it utilises imaging techniques?”

Answer 20

Damasio et al., 1994
* Severe damage to vmPFC bilaterally
* 12 patients with frontal lobe damage.
* Rational decisions & emotional processing.
Phan et al., 2002
* meta-analysis on functional imaging studies showed:
1. The medial prefrontal cortex seemed to have a general
role in emotional processing.
2. Fear activated the amygdala

Question 21

What happened to Elliot?

Answer 21

(Damasio, 1994)
* Tumour frontal lobes
* Prefrontal cortices damaged
* IQ and memory intact post surgery
* Emotionally detached
* Knew emotion but could not feel
* Severance of connections
* Dissociation between knowing and feeling
* Severance of connections frontal cortex and
limbic system

Question 22

What’s the connection between AMYGDALA-ventromedial prefrontal cortexC/orbitofrontal
cortex?

Answer 22

• Strongly anatomically connected (Ghashghaei & Barbas, 2002)
• Amygdala extract affective significance
• Prefrontal cortex guides goal directed behaviour
• VMPFC/orbitofrontal cortex and amygdala involved
  during extinction of conditioned fear response (Phelps et al.,
  2004; Quirk et al., 2003)
• Morgan et al. (1993) demonstrated that lesions to the
  vmPFC led to an impairment in extinction of CER.
• Damaged VMPFC/orbitofrontal cortex: dysregulated
  emotional behaviour (Damasio, Bechara)

Question 23

What are some other brain regions?

Answer 23

• Thalamus
• Hippocampus
• Hypothalamus
• Brain Stem