week 10 Flashcards
(33 cards)
Why are faces considered special to humans?
Faces are unique because they’re critical for person recognition, emotional communication, and social interaction. Humans show early preferences for faces—even newborns prefer cartoonish or schematic faces—and dedicated neural systems have evolved to rapidly process facial information.
What is configural processing, and why is it important for face perception?
Configural processing refers to the analysis of the spatial relationships among facial features. It is essential for recognizing a “likeness” since the overall arrangement (or configuration) of the features carries more identity information than the features in isolation.
How do face identity and facial expression processing differ?
Face identity processing relies on invariant, structural, and configural cues to recognize who someone is, while facial expression processing focuses on dynamic, changeable cues that communicate emotion. These two aspects use distinct but sometimes interacting neural pathways.
What are the core ideas behind face processing models like those of Bruce & Young and Haxby et al.?
Bruce & Young propose that after an initial structural encoding stage, information splits into separate pathways for identity and expression. Haxby et al. describe a distributed neural system with a core system (inferior occipital, fusiform, and superior temporal areas) for processing invariant features and an extended system that handles additional aspects such as emotion and personal identity.
Which neuroimaging and neurophysiological techniques have been used to study face processing?
Researchers use EEG to record ERPs (notably the N170 component), fMRI to localize specialized regions (e.g., FFA, OFA, STS), single‐cell recordings in animals, lesion studies, and brain stimulation to understand the time course and spatial distribution of face processing.
What is pareidolia, and how is it demonstrated in the slides?
Pareidolia is the phenomenon of perceiving faces or meaningful patterns in random or ambiguous stimuli. An example is the detection of a “face on the Moon” or seeing facial features in everyday objects.
How does face processing develop during infancy?
Newborns demonstrate a preference for face-like (often cartoonish) stimuli. By six months, infants can discriminate both human and monkey faces, but by nine months they become specialized for human faces, losing the ability to distinguish monkey faces as easily.
Distinguish between featural and configural processing in face perception
Featural processing involves the analysis of individual facial components (eyes, nose, mouth), which can be recognized regardless of orientation. Configural processing, in contrast, focuses on the spatial relationships among these features, which is especially important for recognizing faces when viewed upright.
What does holistic processing mean in the context of face recognition?
Holistic processing is the integration of the entire face into a unified percept rather than analyzing parts separately. This type of processing makes face recognition particularly sensitive to disruptions in the normal configuration of features.
What is the face inversion effect, and what does it suggest about face processing?
The face inversion effect is the phenomenon where turning a face upside down disproportionately impairs recognition. This supports the idea that normal (upright) face recognition relies heavily on configural and holistic processing.
How does disrupting facial configuration affect the perception of a “likeness” in portraiture?
When a face’s configuration is altered (as in composite face experiments), the overall likeness is lost even if individual features remain accurate. This demonstrates that person recognition depends more on the spatial arrangement of features than on the features themselves.
How do orientation effects differ between featural and configural processing?
Featural processing is relatively invariant to the orientation of individual components, whereas configural processing is highly sensitive to orientation—as seen by the dramatic drop in recognition performance when faces are inverted.
What is the identity aftereffect in face perception?
The identity aftereffect is when prolonged exposure to a particular face causes subsequent ambiguous faces (such as a 50:50 blend) to appear more like the opposite face. This reflects neural adaptation in cells coding for face identity.
What evidence do single-cell recordings provide regarding the processing of face identity versus expression?
Single-cell recordings show that some neurons respond preferentially to invariant features (identity cells) while others respond primarily to dynamic cues (expression cells), demonstrating that the two aspects are managed by distinct neural populations.
How does repetition suppression support the notion of separate neural coding for identity versus expression?
In repetition suppression experiments, repeated presentation of the same identity (with varying expressions) reduces activation in areas like the FFA, whereas repeated expression (across different identities) reduces activity in the anterior STS. This dissociation suggests that identity and expression are processed by separate networks.
Outline the main stages in the Bruce & Young face model.
The model begins with structural encoding of a face, then splits into two main streams: one for processing invariant aspects (leading to face recognition units, person identity nodes, and name retrieval) and another for changeable aspects such as expression and facial speech.
Describe the distributed neural system for face perception as proposed by Haxby et al.
The system includes a core set of regions (inferior occipital gyrus, fusiform gyrus, and superior temporal sulcus) that process the visual aspects of faces, along with an extended system (including anterior temporal regions, amygdala, and other areas) that processes additional information like personal identity and emotion.
What is the N170 ERP component, and why is it significant for face processing research?
The N170 is an ERP component—a strong negative signal occurring around 170 milliseconds after a face is shown. It is significant as it provides a reliable neural marker for early structural encoding of faces, being more prominent for faces than for other objects.
In what way does expertise influence the N170 response?
The N170 can be elicited by both real and schematic faces, indicating that with sufficient exposure (or expertise), the brain becomes adept at recognizing the “faceness” of even abstract or cartoonish stimuli.
Which brain regions have been identified as face-selective, and how have they been investigated?
Key face-selective regions include the Fusiform Face Area (FFA), Occipital Face Area (OFA), and Superior Temporal Sulcus (STS). These have been identified through fMRI studies, lesion analyses, ERP studies, and single-cell recordings in both humans and non-human primates.
What is repetition suppression, and what does it tell us about neural sensitivity in face processing?
Repetition suppression is the reduction in neural activity when a stimulus is presented repeatedly. It indicates that certain brain regions are specifically tuned to particular facial features—such as identity in the FFA or expression in the STS—since these regions “adapt” when the same information is repeatedly processed.
Briefly differentiate between prosopagnosia and Capgras delusion
Prosopagnosia is a deficit in overtly recognizing familiar faces despite intact visual processing, typically due to damage in the ventral route (including the FFA). Capgras delusion, on the other hand, is a disorder in which individuals mistakenly believe familiar people are imposters, implicating disruptions in linking face recognition with emotional response.
How do the dorsal (“where” or “action”) and ventral (“what” or “perception”) pathways contribute differently to face and object recognition
The ventral pathway specializes in processing object identity, form, and invariant features (important for recognizing who someone is), whereas the dorsal pathway processes spatial relationships, motion, and actions, which can influence aspects like dynamic expression and visual speech cues.
What elements of the face are most critical for reading facial expressions?
Critical elements include the eyes, mouth, and the way facial muscles move to form expressions. Variations in eye shape, eyebrow position, and mouth curvature provide vital cues for distinguishing between positive and negative emotions.
