MEMORY SYSTEMS IN THE BRAIN Some Gross Anatomy

The Human Brain saggital section at midline

THE “FUNCTIONAL NEUROANATOMY” of MEMORY Medial temporal lobe structures –Hippocampus –Parahippocampus (entorhinal cortex) Hippocampus and episodic memory –Encoding and consolidation of declarative memory –Role in recent LTM retrieval –Damage leads to “classic” amnesia: severe anterograde declarative deficit –LH verbal, RH spatial?

Lateral temporal lobe structures –retrieval of declarative memory? –Representation of semantic knowledge? –“convergence zones” that index the attributes of an episode? Frontal lobe structures –Lateral regions linked to working memory –Medial regions linked to executive control and attention –Anterior areas most involved in memory function (prefrontal, basal forebrain) –Role in strategic aspects of memory Left: encoding, right: retrieval? (HERA) –Damage leads to deficits in “effortful” aspects of remembering, confabulation

ENCODING-RELATED fMRI and SUBSEQUENT MEMORY Brewer, et al. (1998) –Ss shown color pictures –Scans sorted by later memory –Several areas show memory- specific activation patterns

Diencephalon –Thalamus, Hypothalamus, Mammilary Bodies –Close links to frontal, prefrontal cortex –Role in activation of retrieval process –Damage can lead to amnesia that resembles hippocampal syndrome Basal Ganglia, Cerebellum –Storage, activation of procedural skill and memory –Damage leads to apraxia, deficits in the initiation and control of action “Association” cortices –More “abstracted” than sensory regions –Representation of sensory-motor aspects of memories?

Introducing the Precuneus –Late-maturing association cortex –Just behind Cingulate Gyrus –Highly connected with prefrontal cortex and subcortical structures –High metabolism at rest –Early site of increase in abnormal beta-amyloids in Alzheimer’s Imaging the Precuneus –Visuo-spatial imagery and attention Imagined route-taking –Episodic and autobiographical memory retrieval Source memory for stimuli Family photo recognition –“self-relevant” processes? 1 st vs 3 rd -person short stories Judgments on one’s own traits

The Basal Ganglia - closeup

Cingulate gyrus Precuneus