Abstract 1. The inferior temporal (IT) cortex plays an important role in both short- and long-term memory for visual patterns. Most previous studies of IT neurons have tested their responses in recency memory tasks, which require that the memory lasts only the length of a single behavioral trial, which may be < 1 s. To determine the role of IT neurons in longer lasting memories, we measured their responses to initially novel stimuli as the stimuli gradually became familiar to the animal. 2. Two rhesus monkeys were trained on a delayed matching to sample (DMS) task with several intervening stimuli between the sample and the final matching stimulus on each trial. The purpose of the task was to ensure that the animal attended to the stimuli and held them in memory, at least temporarily. Unlike in several previous studies, the focus was not on within-trial effects but rather on the incidental memories that built up across trials as the stimuli became familiar. Each cell was tested with a set of 20 novel stimuli (digitized pictures of objects) that the monkey had not seen before. These stimuli were used in a fixed order over the course of an hour-long recording session, and the number of intervening trials between repetitions of a given sample stimulus was varied. 3. The responses of about one-third of the cells recorded in anterior-ventral IT cortex declined systematically as the novel stimuli became familiar. After six to eight repetitions, responses reached a plateau that was approximately 40% of the peak response. Virtually all of these cells also showed selectivity for particular visual stimuli and thus were not "novelty detectors" in the sense of cells that respond to any novel stimulus. Rather, the responses of these cells were a joint function of familiarity and specific object features such as shape and color. A few cells showed increasing responses with repetition over the recording session, but these changes were accompanied by changes in baseline firing rate, suggesting that they were caused by nonspecific effects. 4. The decrement in response with familiarity was stimulus specific and bridged > 150 presentations of other stimuli, the maximum tested. For some cells the maximum decrement in response occurred for those stimuli that initially elicited the largest response. There was no significant change in response to stimuli that were already familiar. 5. The same cells that showed familiarity effects also showed reduced responses to the matching stimuli at the end of each trial, compared with the responses to the samples.(ABSTRACT TRUNCATED AT 400 WORDS) Copyright © 1993 the American Physiological Society
Journal of Neurophysiology – The American Physiological Society
Published: Jun 1, 1993
It’s your single place to instantly
discover and read the research
that matters to you.
Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.
All for just $49/month
Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly
Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.
Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.
Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.
All the latest content is available, no embargo periods.
“Hi guys, I cannot tell you how much I love this resource. Incredible. I really believe you've hit the nail on the head with this site in regards to solving the research-purchase issue.”Daniel C.
“Whoa! It’s like Spotify but for academic articles.”@Phil_Robichaud
“I must say, @deepdyve is a fabulous solution to the independent researcher's problem of #access to #information.”@deepthiw
“My last article couldn't be possible without the platform @deepdyve that makes journal papers cheaper.”@JoseServera