1 / 25

Memory for spatial locations, motor responses, and objects

Memory for spatial locations, motor responses, and objects. Group B2 Praveena Simonpillai Koral Neil Katelyn Pirie Pavi Nantheeswarar Sara Silva Nakul Ratra. Outline. Introduction/Background Information - Pavi Experiment 1- Methods and Results - Katelyn & Nakul

simeon
Télécharger la présentation

Memory for spatial locations, motor responses, and objects

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Memory for spatial locations, motor responses, and objects Group B2 PraveenaSimonpillai Koral Neil Katelyn Pirie PaviNantheeswarar Sara Silva NakulRatra

  2. Outline • Introduction/Background Information - Pavi • Experiment 1- Methods and Results - Katelyn & Nakul • Experiment 2- Methods and Results - Sara & Nakul • Experiment 3- Methods and Results - Praveena & Nakul • Discussion and Conclusion - Koral • Questions

  3. Pavi Introduction Key Terms: • Working/ declarative/ data-based memory: memory for new incoming information • Allocentric spatial: spatial location in reference to the outside space and is independent of the viewer • Egocentric spatial: spatial location in reference to the viewer

  4. Pavi Introduction Key Terms

  5. Pavi Two Major Theoretical Views Concerning the Neurobiological Basis of Memory for New Information: 1) Working and Declarative Memory Model: Hippocampus exclusively mediates or codes all info (spatial, temporal, response, sensory-perceptual, or affect) 2) Attribute/ Data-based Memory Model: There are different neural substrates that mediate different attributes.

  6. Pavi Purpose of the Current Study: To determine which of the two models supports the neurobiological basis of memory for new info by testing working/data-based memory for 3 different memory tasks. 3 memory tasks: • spatial location (allocentric) • response (egocentric) • visual object (sensory-perceptual)

  7. Pavi Hypothesis: 1) Based on Working and Declarative Memory Model: • Hippocampal lesion deficits in memory for all 3 tasks But.. • Caudate or extrastriate visual cortex lesions no deficits in memory in 3 tasks 2) Based on Attribute/Data-based Memory Model: • Hippocampal lesion deficit in memory for spatial location task only • Caudate nucleus lesion deficit in memory for motor response task only • Extrastriate nucleus lesion deficit in memory for visual object task only

  8. Pavi Overview of the Current Study Three Experiments: • Experiment 1: spatial location memory task • Experiment 2: motor response memory task • Experiment 3: visual objects memory task

  9. Katelyn Experiment 1:Testing for Spatial Location Memory

  10. Katelyn Step 1 – Training Phase: • Familiarized with maze • Trained using a delayed spatial matching-to-sample procedure Step 2 – Study Phase: • Rats trained to enter a randomly selected arm of the maze to obtain a small piece of cereal (reinforcement) • Rat returned to centre area, linoleum was wrapped around the central platform to cover all arms

  11. Katelyn Step 3 – Test Phase: • Linoleum was removed and rat was given choice between previously entered arm and a new arm • After reaching criterion performance (75% correct or better on 16 consecutive trials) rats received either hippocampal lesions, caudate nucleus lesions, extrastriate visual cortex lesions, or cortical control After Surgery: • Retested 4 times daily until reached criterion performance again • 32 trials (4 per day) with 15 second delay between study and test phase • 32 trials with 30 second delay between study and test phase

  12. Nakul Results - Experiment 1 • Hippocampal lesioned rats • took more trials to rereach • Criterion (P<0.01) • -In the delay tests, continued • poor performance with expected • reduced performance with • increased delay

  13. Sara Experiment 2:Testing for Response Recognition Memory

  14. Sara Step 1 - Training phase: • Familiarized with maze Step 2 - Study phase: • Rat place in middle arm and given opportunity to make left or right turn depending on which door was opened • Given reinforcement for making the right choice Step 3 - Test phase: • Rat was place in middle arm opposite of the study phase arm, both left and right doors were opened and they were given the opportunity to enter one • Positive reinforcement for choosing the matching sample

  15. Sara Post Surgery: • Rats were retested daily until they reached criterion performance or completed 204 trials • Then rats were given 36 trials with a 15-s delay followed by 36 trials with a 30-s delay between study and test phase • All continued testing with a 30-s delay until they reached criterion or 204 trials.

  16. Nakul Results - Experiment 2 • Caudate nucleus lesioned rats • took more trials to rereach • Criterion (P<0.01) • -In the delay tests, continued • poor performance with expected • reduce in performance with • increased delay

  17. Praveena Experiment 3: Testing Visual Object Recognition Memory • Delayed nonmatching-to-sample procedure

  18. Praveena Step 1: Training Phase • Familiarization with apparatus Step 2: Study Phase • Side one of apparatus, rat given opportunity to push aside visual object to obtain reinforcement • On other side, rat must choose novel unique object in order to receive reward • 10 trials per day are given to each rat until 75% criterion or better on 60 consecutive trials has been reached

  19. Praveena Step 3: Test Phase (After Surgery) • Recovered rats are retested daily with 10 trials per day until 75% criterion or better on 60 consecutive trials has been reached • 10s and 20s delay trials done after until criterion reached or after 260 trials

  20. Nakul Results – Experiment 3 • Extrastriate visual cortex • lesioned rats took more • trials to rereach criterion • (P<0.05) • -In the delay tests, • continued poor performance • with expected reduce in • performance with • increased delay

  21. Nukal Summary of Results

  22. Koral

  23. Koral DISCUSSION/CONCLUSION Also, all 3 tasks used similar S-R bonds and CMM ie:moving towards or away from set target. • HIPPOCAMPUS LESIONS spatial location recall deficits. Findings were consistent with previous neurobiological studies of monkeys (eg. Hunt et al 1986) and humans (eg. Cave and Squire, 1991). • CAUDATE NUCLEUS LESIONS response recognition memory deficits. Consistent with previous studies. • MEDIAL EXTRASTIATE VISUAL CORTEX LESION visualobject recognition deficits. Consistent withpreviousstudies (eg Farah, 1990 – visualappreceptiveagnosia). MEVC – parallelfunction to hippocampusmediation of WM for visualobjects.

  24. Koral KEY FINDINGS • TRIPLE DISSOCIATION of the hippocampus, caudate nucleus and areas of extrastriate visual cortex in mediation of spatial location, visual object processing and responding functions. • Each neural systems can function independently in STM and in parallel. • More than the H mediates WMM – first hypothesis refuted. • Revision of Kesner’sattributememory model needed - multidimensionalmemory model • Each of the 3 lesioned rats performed well in at least 2 STM tasks - low reliability and causality of MD to GA, M, AP or pre-surgery training.

  25. Thank you for listening!

More Related