Brain and behaviour session 7: How does Alzheimer's disease affect psychological
functioning?
Episodic memory (remembering recent events) - Atrophy in medial temporal lobes
Semantic memory and language (understanding and producing words) - Atrophy in
anterior temporal and inferior frontal cortex
Controlling thought and behaviour - Atrophy in frontal cortex. Effects on personality
The case of Iris Murdoch
AD causes widespread brain atrophy, particularly affecting temporal, parietal and
frontal lobes. Different areas of atrophy can be linked to different deficits.
How does Alzheimer’s disease affect psychological functioning?
1. Episodic memory
The earliest signs of AD are often forgetfulness and inability to remember recent
events. In moderate AD, people also show disorientation and wandering – these
impairments might be linked to atrophy of the hippocampus.
Hippocampus embedded within the temporal lobes, one each hemisphere
Memory in Alzheimer’s disease
Recall: you have to find a way of ‘finding’ the relevant memory traces
Recognition: seeing the item again acts as a potent cue
Deficit for both recall and recognition in early AD
AD damages formation of memory traces themselves; it is not just a problem with
retrieval (i.e., finding the information)
Backman et al. (2001) Brain, 124, 96-102
Method: Repeated free recall (FR) and recognition (RN) with >100 older adults.
Picked out those who developed dementia. Looked at performance 3 and 6 years
before diagnosis of dementia
Free recall is easier than recognition in both groups
Recognition and recall are similarly impaired
This impairment can be seen even 6 years before diagnosis
Little change over time (are AD getting worse, or were they better premorbidly? – cf.
cognitive reserve)
Episodic memory is poorer in patients before they develop AD
Mild Cognitive Impairment (MCI)
Whitwell et al. (2007) Brain, 130, 1777-86.
Brain volume differences compared with healthy controls.
Shrinkage in anterior, Inferior and medial temporal lobes (including hippocampus)
before diagnosis.
Pattern of atrophy and neuropsychology both suggest episodic memory deficits at
early stages of AD
2. Semantic memory and language
The left hemisphere is dominant for most aspects of language processing (in most
people).
Anterior temporal lobe (front part) and the inferior frontal lobe (lower part) are
important for understanding and producing words. Atrophy here produces semantic
and language deficits in AD.
Category fluency task - Forbes-McKay, K. E., Ellis, A. W., Shanks, M. F., & Venneri, A.
(2005). Neuropsychologia, 43, 1625-1632
functioning?
Episodic memory (remembering recent events) - Atrophy in medial temporal lobes
Semantic memory and language (understanding and producing words) - Atrophy in
anterior temporal and inferior frontal cortex
Controlling thought and behaviour - Atrophy in frontal cortex. Effects on personality
The case of Iris Murdoch
AD causes widespread brain atrophy, particularly affecting temporal, parietal and
frontal lobes. Different areas of atrophy can be linked to different deficits.
How does Alzheimer’s disease affect psychological functioning?
1. Episodic memory
The earliest signs of AD are often forgetfulness and inability to remember recent
events. In moderate AD, people also show disorientation and wandering – these
impairments might be linked to atrophy of the hippocampus.
Hippocampus embedded within the temporal lobes, one each hemisphere
Memory in Alzheimer’s disease
Recall: you have to find a way of ‘finding’ the relevant memory traces
Recognition: seeing the item again acts as a potent cue
Deficit for both recall and recognition in early AD
AD damages formation of memory traces themselves; it is not just a problem with
retrieval (i.e., finding the information)
Backman et al. (2001) Brain, 124, 96-102
Method: Repeated free recall (FR) and recognition (RN) with >100 older adults.
Picked out those who developed dementia. Looked at performance 3 and 6 years
before diagnosis of dementia
Free recall is easier than recognition in both groups
Recognition and recall are similarly impaired
This impairment can be seen even 6 years before diagnosis
Little change over time (are AD getting worse, or were they better premorbidly? – cf.
cognitive reserve)
Episodic memory is poorer in patients before they develop AD
Mild Cognitive Impairment (MCI)
Whitwell et al. (2007) Brain, 130, 1777-86.
Brain volume differences compared with healthy controls.
Shrinkage in anterior, Inferior and medial temporal lobes (including hippocampus)
before diagnosis.
Pattern of atrophy and neuropsychology both suggest episodic memory deficits at
early stages of AD
2. Semantic memory and language
The left hemisphere is dominant for most aspects of language processing (in most
people).
Anterior temporal lobe (front part) and the inferior frontal lobe (lower part) are
important for understanding and producing words. Atrophy here produces semantic
and language deficits in AD.
Category fluency task - Forbes-McKay, K. E., Ellis, A. W., Shanks, M. F., & Venneri, A.
(2005). Neuropsychologia, 43, 1625-1632
