Immediate Memory Processing Without Rehearsal

The Phonological loop of working memory is a research focus of current cognitive psychology and cognitive neuropsychology. This paper looks back the newest model and functional anatomy of working memory, the structure,function and neuroanatomical substrates of phonological loop. Using delayed-response paradigms to enhance rehearsal is a key design feature in most former studies of immediate memory of VWM. However the neuroanatomical substrates of phonological store and the function of rehearsal in phonological loop remain underdetermined.The aim of this fMRI study was to identify neuroanatomical substrates of immediate memory underlying phonological processing. To distinguish encoding of immediate memory from rehearsal, this study uses immediate recognition paradigm of non-fixed memory length. Presented different auditory signal including memory cluster and probe stimulus, participants were required to judge whether the phoneme units of the following probes, including consonants, rhymes and tones, have appeared in former memory cluster or not.This study is block design, including three series: consonants, rhymes and tones. Moreover, every series include fixed tasks contrast to random tasks. In consonants series, Participants were asked to selectively attend to targeted sub-syllabic components, and make same-different judgement between the consonant of probe syllable and the first syllable of former memory cluster in fixed tasks; in contrast, in random tasks, Participants were asked to identify whether the consonant of probe syllable have appeared in random position of former memory cluster or not. The experiment procedure of Rhyme serials and tone serials were similar to consonant serials, except to the judgement of rhyme and judgement of tone.The co-active region of three serials relative to a resting baseline would indentify the anatomical substrates of phonological store. Relative to fixed tasks, immediate memory scanning was pinpionted in random immediate reconition tasks. Memory scanning also reflects the anatomical network of immediate memory store and processing. So, we have chance to explore the anatomical substrates of phonological store. Increased activations were found in the left inferior frontal gyrus, medial frontal gyrus, inferior parietal cortex, anterior cingulated cortex (ACC), Occi-temproal areas. These neuronetwork may be involved in memory scanning and are relative to store and extract phoneme information.