Memory

The Case of H.M.

Figure MRI scans of the normal and damaged hippocampus Klein/Thorne: Biological Psychology © 2007 by Worth Publishers

Changes since lobectomy Only one or two minor seizures per day Reduced medication IQ was slightly above average Normal perceptual and motor abilities Serious problems with memory ml?_r=1&pagewanted=1&emhttp:// ml?_r=1&pagewanted=1&em

Memory Tests

Memory tests he could not do as well as a normal person Digit Span + 1 Test Block-Tapping + 1 Test

This is why… Short-term memory was fine –STM stores a limited amount of information for a limited amount of time (about 15 seconds) Long-term memory was compromised –LTM stores an unlimited amount of information for an unlimited amount of time

Other Memory Tests

Figure The mirror tracing task Klein/Thorne: Biological Psychology © 2007 by Worth Publishers Mirror-Drawing Test

Rotary-Pursuit Task

Declarative vs. Procedural memory Declarative memory Digit span Block tapping Procedural memory Mirror drawing Rotary pursuit

Explicit vs. Implicit memory

H. M.’s Memory Problems Mild retrograde amnesia –Events that happened before surgery; e.g. where he went to elementary school Severe anterograde amnesia –Events that happened after surgery

Other Distinctions Semantic memory General facts Information E.g. Episodic memory Particular events or experiences in one’s life E.g.

Figure 14.4 Types of long-term memory Klein/Thorne: Biological Psychology © 2007 by Worth Publishers

The Atkinson-Shiffrin Model Memory storage has three stages Sensory register –0.5 to 1 second Short-term store –Duration depends on Rehearsal Amount of information – distraction Long-term store –Permanent

The Atkinson-Shiffrin Model Interference –Retroactive interference –Proactive interference

Posttraumatic Amnesia

Normal functioning Retrograde amnesia Blow to the head Anterograde amnesia Normal functioning

Consolidation Converting short-term memory to long-term memory

Consolidation Hebb’s theory An experience triggers activity in a circuit of neurons in the central nervous system –Reverberation The circuit of neurons is called a “cell assembly” Eventually, the neurons in the cell assembly change (e.g., shape of terminal button, number of receptors) This causes memories to be now be stored in the long term

Consolidation If process is disrupted, then unable to permanently store new memory –ECT Problem with this theory: the period of retrograde amnesia can be for years

Role of the Hippocampus in Memory Figure 2.23 The limbic system Klein/Thorne: Biological Psychology © 2007 by Worth Publishers

Role of the Hippocampus in Memory Hippocampus is part of the limbic system, in the forebrain The hippocampus is involved in storing new memories

Frontal and temporal lobes Frontal and temporal lobes are active during retrieval of memories

Other Parts of the Brain Associated with Memory

Amygdala Memories for frightening events Figure 2.23 The limbic system Klein/Thorne: Biological Psychology © 2007 by Worth Publishers

Prefrontal cortex Long-term working memory Cooking Thanksgiving dinner Figure 2.25 The cerebral cortex, dorsal and lateral views Klein/Thorne: Biological Psychology © 2007 by Worth Publishers

Cerebellum Learned movements

Why you should not cram when studying for exams protein phosphatase 1

Why you should not cram when studying for exams Notes

Dr. Elizabeth Loftus Loftus (2003)

Discussion Your memories of your past have a great influence on your sense of who you are as a unique person. Yet, as Elizabeth Loftus demonstrated, memories are easily altered or distorted. What implications does this have with regard to a person’s sense of self?

What are the broader implications of Loftus’ findings? What are the limitations of Loftus’ findings?