کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
936517 1475149 2015 17 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Learning strategy refinement reverses early sensory cortical map expansion but not behavior: Support for a theory of directed cortical substrates of learning and memory
ترجمه فارسی عنوان
پالایش استراتژی یادگیری، تغییر شکل داده شده در ابتدای سنسور کورکتال را پیش می کشد، اما نه رفتار: حمایت از یک نظریه از زیر ساختارهای هدایت شده یادگیری و حافظه
کلمات کلیدی
یادگیری وابسته قشر شنوایی، پلاستیک کرمی، بیش فعالی پلاستیکی نمایشی، تئوری سطح سیستم
موضوعات مرتبط
علوم زیستی و بیوفناوری علم عصب شناسی علوم اعصاب رفتاری
چکیده انگلیسی


• Learning expands the representation of a sensory signal in primary sensory cortex.
• Extensive overtraining after task solution can eliminate the expanded representation.
• Rats solved a three-tone discrimination using a strategy expanding CS+ representation.
• Animals that changed strategy during overtraining lost their expanded representation.
• Understanding cortical substrates of learning requires determining strategies used.

Primary sensory cortical fields develop highly specific associative representational plasticity, notably enlarged area of representation of reinforced signal stimuli within their topographic maps. However, overtraining subjects after they have solved an instrumental task can reduce or eliminate the expansion while the successful behavior remains. As the development of this plasticity depends on the learning strategy used to solve a task, we asked whether the loss of expansion is due to the strategy used during overtraining. Adult male rats were trained in a three-tone auditory discrimination task to bar-press to the CS+ for water reward and refrain from doing so during the CS− tones and silent intertrial intervals; errors were punished by a flashing light and time-out penalty. Groups acquired this task to a criterion within seven training sessions by relying on a strategy that was “bar-press from tone-onset-to-error signal” (“TOTE”). Three groups then received different levels of overtraining: Group ST, none; Group RT, one week; Group OT, three weeks. Post-training mapping of their primary auditory fields (A1) showed that Groups ST and RT had developed significantly expanded representational areas, specifically restricted to the frequency band of the CS+ tone. In contrast, the A1 of Group OT was no different from naïve controls. Analysis of learning strategy revealed this group had shifted strategy to a refinement of TOTE in which they self-terminated bar-presses before making an error (“iTOTE”). Across all animals, the greater the use of iTOTE, the smaller was the representation of the CS+ in A1. Thus, the loss of cortical expansion is attributable to a shift or refinement in strategy. This reversal of expansion was considered in light of a novel theoretical framework (CONCERTO) highlighting four basic principles of brain function that resolve anomalous findings and explaining why even a minor change in strategy would involve concomitant shifts of involved brain sites, including reversal of cortical expansion.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Neurobiology of Learning and Memory - Volume 126, December 2015, Pages 39–55
نویسندگان
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