Section 5 Practice Questions Flashcards
(15 cards)
Describe the attentional enhancemen effect and its implications for perception
The attentional enhancement effect shows that attention to a grating increases its perceived contrast – even when actual contrast remains constant. This suggests that attention can modify perceptual experience by enhancing stimulus features at the attended location.
What is the spatial cuing paradigm, and what does it reveal about selective attention?
Involves presenting cues that direct attention to a location where a target may appear. Reaction times are fastest when the cue is valid (target appears at cued location), slower for neutral cues, and slowest for invalid cues
How does attention modulate neural response in visual cortex according to Moran & Desimone?
When both a preferred and a non-preferred stimulus are in a neuron’s receptive field (RF), attention directed to the preferred stimulus increases the neuron’s firing rate
Compare parallel and serial visual search and explain when each occurs.
In parallel search, all objects are processed simultaneously, and therefore, search time is unaffected by set size. Parallel search occurs when targets can be identified by a single feature. In serial search, attention shifts from one object to the next and therefore search time increases with set size
What is feature integration theory, and how does it address the binding problem?
Proposes that simple features are processed preattentively and in parallel, but attention is required to bind those features into coherent objects during a focused attention stage. This solves the binding problem (attention acts as a glue that integrates the features together.
Explain the components of a pressure wave and how they relate to hearing
A pressure wave consists of compression and rarefraction. These fluctuations cause the eardrum to vibrate, initiating a chain of mechanical and neural processes that result in the perception of sound
What is the function of the ossicles in the middle ear, and how do they overcome the air-to-water impedance problem?
The ossicles (malleus, incus, stapes) amplify sound by concentrating vibration from the eardrum onto the smaller oval window and using leverage.
Describe the process of auditory transduction in the cochlea
Sound waves cause the basilar membrane to vibrate, moving the Organ of Corti. This causes a shearing force on the hair cells, opening ion channels, and leading to depolarization. The resulting electrical signal is transmitted via spiral ganlgion cells to the auditory nerve.
What is the difference between place and frequency theories of pitch perception
Place theory posits that pitch is coded by the location of peak vibration on the basilar membrane
Frequency theory suggests pitch is coded by the firing rate of hair cells
Place-frequency theory integrates both (frequency < 500 Hz; place > 500 Hz)
How is loudness encoded in the auditory system
Loudness is encoded by firing rate of hair cells and by the number of cells activated, especially at lower frequencies.
What is the segmentation problem in speech, and how do listeners solve it?
The segmentation problem arises since there are no clear boundaries between spoken words in the acoustic signal. It is resolved through top-down processing which uses contextual cues and existing knowledge of language to infer where one word ends and another begins.
Define categorical perception in speech and explain the significance of VOT experience
Categorical perception is the phenomenon where continuous changes in acoustic signals are perceived as discrete phoneme categories. VOT studies show sharp boundaries in perception despite gradual changes in stimulus (highlights the brain’s role in organizing speech sounds)
What is the McGurk effect and what does it reveal about speech perception?
The McGurk effect occurs when conflicting auditory and visual speech inputs (e.g., hearing ba and seeing a) result in the perception of a third phoneme (e.g,. da). This demonstrates multisensory integration in speech perception, showing that vision influence what we hear
Describe the phoneme restoration effect
The phoneme restoration effect refers to the brain’s ability to fill in missing phonemes obscured by noise (e.g. cough) based on contextual information through top-down processing.
How does experience-dependent plasticity affect phoneme perception?
Infants can distinguish phonemes from all languages, but exposure to a specific language tunes their auditory system to those phonemes. Over time, the ability to distinguish non-native phonemes declines, demonstrating the brain’s plasticity based on linguistic experience.
