Brain regions associated with retrieval of structurally coherent visual information

Area of Science:

• Neuroscience
• Cognitive Psychology
• Neuroimaging

Background:

• The brain utilizes specialized regions, including the inferior temporal cortex, for representing object structures.
• Understanding this system involves studying how humans process novel objects with coherent or incoherent three-dimensional forms.

Purpose of the Study:

• To investigate the neural basis of representing three-dimensional object structures.
• To differentiate brain activity related to decisions about possible versus impossible object structures.
• To examine the role of the hippocampal formation in object recognition memory.

Main Methods:

• Participants studied drawings of novel objects with possible or impossible structures.
• Behavioral tasks included making object structure decisions and old/new recognition decisions.
• Positron emission tomography (PET) was used to measure regional cerebral blood flow.

Main Results:

• Object decisions about possible objects were facilitated by prior study, unlike impossible objects.
• Increased blood flow in inferior temporal regions correlated with decisions about possible objects, not impossible ones.
• The hippocampal formation showed increased activity during episodic recognition of possible objects.

Conclusions:

• The inferior temporal cortex is crucial for representing structurally coherent visual objects.
• Episodic memory for objects involves the hippocampal formation.
• Neural activity patterns distinguish between processing object structure and recognizing object familiarity.