WM part 1

• H.M.


  Bilateral removal of the temporal lobe
• H.M. case 


  • Severe amnesia - inability to form new LT memories for events and facts
  • Preserved ST memory
  • Preserved procedural memory
• K.F.


  Lesion to parietal/occipital cortex
• K.F.


  • Impaired digit span (ST mem = approx. 2 items)
  • Preserved LT memory
• Double Dissociation between LT & ST memory

  Patient is impaired on process X but has preserved process Y and another patient is impaired on process Y but preserved on process X
• Double Dissociation can only occur if 2 functions depend on separate brain regions
• Working Memory


  • Visuospatial sketchpad & phonological loop = storage
  • Central executive = executive functions
• Articulatory suppression effect suggests existence of 2 separate systems for temporary storage of info, 1 phonological and 1 visuospatial
• Fuster (1974)


  • Monkeys see piece of food, shutter comes down and closes tray, when shutter opens monkey has to remember where food was
  • Single neuron recordings from PFC showed elevated neuronal firing during delay period - when the shutter is down
• Elevated neuronal firing in PFC during delay period shows neurons in PFC hold a representation of the to-be-remembered stimulus
• Goldman-Rakic (1987): Standard model of WM


  • Sustained activation in PFC during delay period of WM task reflects a neuronal WM 'template' - temporary representation of to-be-remembered info
  • PFC activity reflects neuronal instantiation of Baddeley's WM storage buffers
• Direction-specific firing of PFC neurons during delay period shows a direct neurophysiological correlate of WM template - a temp representation of spatial location indicated by cue
• PFC holds a representation of to-be-remembered info over short periods of time of WM task
• What vs Where in WM

  2 types of visuospatial WM - 1 for objects & 1 for spatial locations
• General Intelligence (Spearman's 'g' factor)


  • Correlations in kids between diff disparate measures - academic ability & sensory discrimination
  • Factor analysis revealed underlying factor common to performance of many different kinds of tasks ('g' factor) - general intelligence
• Gf - Fluid intelligence


  • Reasoning
  • Problem solving
• Gc - Crystallised intelligence


  General knowledge
• Monkeys are better than humans at working memory
• Performance on WM tasks depends on a combo of storage (ST memory) and executive processes (WM)
• Working component of WM, not simple STM, predicts fluid intelligence
• Fluid, or general, intelligence involves the 'executive attention' component of WM