The long-term effect of perspective change on the emotional intensity of autobiographical memories.

Autobiographical memories can be recalled from either a field (first-person) or an observer (third-person) perspective. Previous studies have reported that field-to-observer perspective change reduced the emotional intensity of recalled events. In the present study, we examined whether this effect has a long duration by employing follow-up measurements. The participants were asked to recall the same events repeatedly across three sessions (S1, S2, and S3): S2 was conducted about three days after S1, and S3 was conducted about four weeks after S2. The results showed a reduction in the emotional intensity of the recalled events when the perspective was changed from field to observer at S2. More importantly, this reduction in emotional intensity persisted until S3. These effects were not observed under observer-to-field perspective change at S2. These results suggest that observer perspective taking can cause plastic change in the autobiographical memory system.

Abnormal Wrist Sagittal Kinematics in Gymnasts With Dorsal Wrist Pain: A New Syndrome.

BACKGROUND: The pathology of dorsal wrist pain in gymnasts without abnormal radiographic findings remains unclear. PURPOSE/HYPOTHESIS: The purpose of this study was to identify abnormal wrist sagittal kinematics in gymnasts with dorsal wrist pain. It was hypothesized that gymnasts with dorsal wrist pain would show abnormal sagittal kinematics with reversible hypermobility of the intercarpal joint. STUDY DESIGN: Controlled laboratory study. METHODS: Participants included 19 wrists in male gymnasts with dorsal wrist pain, 18 wrist in male gymnasts without wrist pain, and 20 adult men without a history of wrist pain. Magnetic resonance imaging (T2-weighted sagittal images) findings at 0°, 30°, 60°, and 90° of wrist extension were used in kinematic analysis. The angles and translations of the radiolunate, capitolunate, and third carpometacarpal joint were measured and compared between the 3 groups. RESULTS: At 90° of wrist extension, gymnasts with dorsal wrist pain had a significantly lower radiolunate joint angle (28.70°± 6.28° vs 36.19°± 7.81°; P = .020) and a significantly higher capitolunate joint angle (57.99°± 6.15° vs 50.50°± 6.98°; P = .004) and distal translation (1.17 ± 0.50 mm vs 0.46 ± 0.62 mm; P = .002) than gymnasts without dorsal wrist pain. CONCLUSION: Gymnasts with dorsal wrist pain showed abnormal wrist sagittal kinematics. These novel findings may facilitate understanding of dorsal wrist pain, which can be recognized as a new syndrome termed "gymnast's lunate dyskinesia."

A missense mutation in the Hspa8 gene encoding heat shock cognate protein 70 causes neuroaxonal dystrophy in rats.

Neuroaxonal dystrophy (NAD) is a neurodegenerative disease characterized by spheroid (swollen axon) formation in the nervous system. In the present study, we focused on a newly established autosomal recessive mutant strain of F344-kk/kk rats with hind limb gait abnormalities and ataxia from a young age. Histopathologically, a number of axonal spheroids were observed throughout the central nervous system, including the spinal cord (mainly in the dorsal cord), brain stem, and cerebellum in F344-kk/kk rats. Transmission electron microscopic observation of the spinal cord revealed accumulation of electron-dense bodies, degenerated abnormal mitochondria, as well as membranous or tubular structures in the axonal spheroids. Based on these neuropathological findings, F344-kk/kk rats were diagnosed with NAD. By a positional cloning approach, we identified a missense mutation (V95E) in the Hspa8 (heat shock protein family A (Hsp70) member 8) gene located on chromosome 8 of the F344-kk/kk rat genome. Furthermore, we developed the Hspa8 knock-in (KI) rats with the V95E mutation using the CRISPR-Cas system. Homozygous Hspa8-KI rats exhibited ataxia and axonal spheroids similar to those of F344-kk/kk rats. The V95E mutant HSC70 protein exhibited the significant but modest decrease in the maximum hydrolysis rate of ATPase when stimulated by co-chaperons DnaJB4 and BAG1 in vitro, which suggests the functional deficit in the V95E HSC70. Together, our findings provide the first evidence that the genetic alteration of the Hspa8 gene caused NAD in mammals.

[Comparison of the specificity of musically cued autobiographical memories].

This paper compared the specificity of recollections of autobiographical memories where musical cues for events were varied. We used music which was popular in the past as cues which were related to a larger number of past individual events (frequent events cues) and music which was typically only sung at graduation ceremonies as cues which were related to a smaller number of events (rare events cues). In the instructed retrieval condition, participants were told to listen to the music and to recall past events, whereas in incidental retrieval condition, the instruction was only to listen to the music. Then participants were asked to describe what they recalled while hearing the music. When frequent events musical cues were played, the specificities of the recalled events were higher in the instructed retrieval condition than in the incidental retrieval condition. In contrast, when rare events musical cues were played, there were no differences in the specificities of the recalled events.

Individual traits that influence the frequency and emotional characteristics of involuntary musical imagery: An experience sampling study.

In this study, we investigated individual traits that influence the frequency of involuntary musical imagery (INMI) and the emotional valence of these occurrences using the experience sampling method (ESM) that measures INMI in daily life at the moment they occur. As individual traits, the effects of non-clinical obsessive-compulsive (OC) tendencies, personality traits, and musical expertise were examined. Among them, we were particularly interested in the effect of OC tendencies that are assumed to be related to INMI but are yet to be fully examined using ESM. A total of 101 university students completed questionnaires that assessed OC tendencies, the Big Five personality traits, and musical expertise. During the seven-day sampling period, participants received smartphone notifications six times per day and responded by stating whether they had experienced INMI and described the emotional characteristics of those occurrences. A multilevel analysis showed the relationship between OC tendencies and INMI. A positive effect was observed for intrusive thoughts (obsession) on the occurrence of INMI. Regarding the emotional characteristics of INMI, a negative effect of compulsive washing was observed on both the pleasantness of INMI experiences and the extent to which the participants liked the music they had heard internally. The effects of both personality traits and musical expertise were also observed in the analysis of INMI occurrences, both of which are consistent with previous findings. In summary, the present study using ESM supports previous findings on individual traits that affect INMI and clarifies them with additional detail and accuracy.

Task-unrelated thought depends on the phonological short-term memory system more than the visual short-term memory system.

This study examined which type of short-term memory (STM), phonological or visual, is involved in and more important for representing contents of task-unrelated thoughts (TUTs). Three experiments consistently showed that TUTs were less likely to be reported during phonological STM tasks than either visual STM or control tasks. In contrast, the number of TUT responses did not considerably differ between visual STM tasks and control tasks even for TUTs with many visual images. This difference cannot be explained by the differential involvement of executive control processes because task difficulty was controlled for in the multi-level logistic regression analysis. These results, together with the finding that most TUT responses contained verbal images, suggest that phonological STM plays an important role in representing verbal images in TUTs, while visual STM is less or not involved in representing TUTs, even for those with many visual images.

Stroop performance and difficulties of older adults using automatic teller machines.

This study examined the relationship between inhibition of older dults and difficulties using automatic teller machines. 22 older adults performed three transactions on an ATM simulator, and errors were recorded. Participants also performed the Stroop interference task to assess inhibition. Both interference effect in response latencies and rate of intrusion errors in the Stroop task were moderately correlated with number of errors on the task. Older adults with low Stroop performance made more errors in the categories of Forgetting an operation, Screen mix-up, and Overlooking an input error than those with high performance. These results suggest that low inhibition may be associated with difficulties in automatic teller machine use, and the importance of designing a user interface which lessens the likelihood of errors for older adults or others.

The effect of the number of possible words on word completion: a magnetoencephalographic study.

We examined the effect of the number of possible words in a word completion task on left superior temporal activity using magnetoencephalography. If this area is involved in access to phonological word representations, as assumed in dual-route models of reading, its activation for word fragments having many possible words (Many condition) would be greater than for fragments with one possible word (Single condition). Left superior temporal activity did not differ in strength between the conditions, while behavioral data suggested multiple accesses in the Many condition. Activation was shorter in the Many than in the Single condition, probably owing to bigram frequency difference. These results are inconsistent with the view that the left superior temporal area is related to lexical-route processing.

[Experimental study of the emotional valence of involuntarily recalled autobiographical memories].

Involuntary recollection of autobiographical memories refers to memories of personal experiences that pop into consciousness with no preceding attempts at remembering. In a laboratory experiment, we examined the effect of emotional valence on the involuntary recollection of autobiographical memories. Participants evaluated the familiarity of four words referring to various events (cues for autobiographical recollection) and then reported whether they had unintentionally recalled past experiences during these evaluations. We manipulated the emotional valence (positive/negative) and specificity (specific/common) of the cue words. In the specific-event condition, cue words for positive events elicited more involuntary memories than those for negative events. In addition, the mean frequency of recollection was higher in the specific-event condition than that in the common-event condition. These results are consistent with studies that used diary methods, which showed a dominance of positive events in involuntary recollection of autobiographical memories.

Individual differences in face memory and eye fixation patterns during face learning.

This study examined the relationship between individual differences in face memory and eye fixation patterns during face learning. Participants watched short movies of 20 faces and were divided into high and low face memory groups based on their performance in a recognition memory test. No qualitative difference was observed in the eye fixation distribution between high and low groups. Both groups mostly fixed on the internal region of faces, especially the eyes. A difference in the eye fixation pattern by groups was observed in the number of fixations and total fixation time on the eyes, which reflected high face memory participants moving their eyes between the left and right eyes more frequently than low face memory participants. These findings suggest that fixation on the eyes has a functional role in face memory and is related to individual differences in face memory.

Concentrated pitch discrimination modulates auditory brainstem responses during contralateral noise exposure.

This study examined a notion that auditory discrimination is a requisite for attention-related modulation of the auditory brainstem response (ABR) during contralateral noise exposure. Given that the right ear was exposed continuously with white noise at an intensity of 60-80 dB sound pressure level, tone pips at 80 dB sound pressure level were delivered to the left ear through either single-stimulus or oddball procedures. Participants conducted reading (ignoring task) and counting target tones (attentive task) during stimulation. The oddball but not the single-stimulus procedures elicited task-related modulations in both early (ABR) and late (processing negativity) event-related potentials simultaneously. The elicitation of the attention-related ABR modulation during contralateral noise exposure is thus considered to require auditory discrimination and have the corticofugal nature evidently.

An ignoring task improves validity of cortical evoked response audiometry.

This study examined the basis for introducing an ignoring task during cortical evoked response audiometry (CERA) using the N1-P2 response. Healthy hearing participants were assigned to two groups with and without an ignoring task (ignoring and listening groups) during CERA whose outcomes were compared with the pure-tone audiometry (PTA) in response to tone frequencies at 500-4000 Hz. The ignoring but not the listening group exhibited positive correlations between the PTA and CERA thresholds, and further showed negative correlations between the PTA threshold and the N1-P2 amplitude as the tone intensity decreased particularly for lower tone frequencies. Within the healthy hearing levels at least, conducting an ignoring task is thus considered to improve the validity of CERA for lower tone frequencies.

Attention-related modulation of auditory brainstem responses during contralateral noise exposure.

As determinants facilitating attention-related modulation of the auditory brainstem response (ABR), two experimental factors were examined: (i) auditory discrimination; and (ii) contralateral masking intensity. Tone pips at 80 dB sound pressure level were presented to the left ear via either single-tone exposures or oddball exposures, whereas white noise was delivered continuously to the right ear at variable intensities (none--80 dB sound pressure level). Participants each conducted two tasks during stimulation, either reading a book (ignoring task) or detecting target tones (attentive task). Task-related modulation within the ABR range was found only during oddball exposures at contralateral masking intensities greater than or equal to 60 dB. Attention-related modulation of ABR can thus be detected reliably during auditory discrimination under contralateral masking of sufficient intensity.

Effects of lexical prosody and word familiarity on lexical access of spoken Japanese words.

Lexical prosody (e.g., stress and pitch accent) has been shown to constrain lexical activation of spoken words in various languages. In the present study, whether or not the constraint of lexical prosody is affected by word familiarity in lexical access of Japanese words was examined using a cross-modal priming task. The stimuli were pairs of prosodically different homophones (minimal accent pairs). When the targets were more familiar members of minimal accent pairs, the responses were facilitated by prior presentations of primes that were prosodically different homophones of the targets, suggesting that lexical prosody did not constrain lexical activation. In contrast, when less familiar members of minimal accent pairs were used as the targets, the prosodically different homophones did not facilitate the responses to the targets. These results suggest that the constraint of lexical prosody is not so strong but is affected by the factor of word relative familiarity.

Attention effects at auditory periphery derived from human scalp potentials: displacement measure of potentials.

It is known in humans that electrophysiological measures such as the auditory brainstem response (ABR) are difficult to identify the attention effect at the auditory periphery, whereas the centrifugal effect has been detected by measuring otoacoustic emissions. This research developed a measure responsive to the shift of human scalp potentials within a brief post-stimulus period (13 ms), that is, displacement percentage, and applied it to an experiment to retrieve the peripheral attention effect. In the present experimental paradigm, tone pips were exposed to the left ear whereas the other ear was masked by white noise. Twelve participants each conducted two conditions of either ignoring or attending to the tone pips. Relative to averaged scalp potentials in the ignoring condition, the shift of the potentials was found within early component range during the attentive condition, and displacement percentage then revealed a significant magnitude difference between the two conditions. These results suggest that, using a measure representing the potential shift itself, the peripheral effect of attention can be detected from human scalp potentials.

The effect of phonological repetition on cortical magnetic responses evoked by visually presented words.

Neuroimaging studies have reported that the left superior temporal cortical area is activated by visually presented words. In the present study, we recorded cortical magnetic responses evoked by visual words and examined the effect of phonological repetition (e.g., hair-hare) on left superior temporal cortical activity, using pairs of homophonic Japanese words as stimuli. Unlike English, Japanese has a large number of homophone pairs with a totally different orthography. By taking advantage of this feature of the Japanese writing system, the effect of phonological repetition can be solely examined without being confounded by the effect of orthographic similarity. Magnetic responses were recorded over the bilateral temporal sites of the brain while subjects silently read words. The words were presented one by one; a quarter of them was immediately followed by a homophonic word. Clear magnetic responses in the latency range of 300-600 msec were observed in the left hemisphere, and the responses to the homophones were smaller than those to the first presented words. In the right hemisphere, clear responses were not consistently recorded in the same latency range, and no effect of phonological repetition was observed. The sources of the responses recorded over the left hemisphere were estimated to be in the left superior temporal cortical area adjacent to the auditory cortex and the source strength as well as the magnetic responses showed a reduction by phonological repetition. This result suggests that the activity in the left superior temporal cortical area is associated with access to the phonological representation of words.