Event-related brain potentials: report order and task switch on multidimensional stimuli identification

An experiment was conducted to evaluate the effect of order of reporting stimulus dimension in multidimensional stimulus identification using a switch-task paradigm. Participants were required to identify each two-dimensional symbol by pushing the corresponding buttons on the keypad on which there were two columns representing the two dimensions, part and shape. The two orders of report were Order Part/Shape and Order Shape/Part. There was a task cue prior to each presentation of a symbol indicating the particular report order the participants should perform. The cue changed randomly. Both behavioral data and event-related potentials were recorded from 12 college students. Analysis of behavioral data showed switch cost indicated by increase in response time was greater for Order Shape/Part, a less appropriate order of reporting dimensional values, than Order Part/Shape (88 msec. vs 9 msec. for response time for the first stimulus dimension; 96 msec. vs -1 msec. for response time total). Neural activities under Order Shape/Part and Order Part/Shape were different, and it seems plausible that participants put more effort into selection and showed more related semantic activation in Order Shape/Part than in Order Part/ Shape which fits the Chinese adjective-then-noun language habit.     

Extraversion and neuroticism in orienting reflex dishabituation

The present study examined the effects of extraversion (E) and neuroticism (N) as individual difference dimensions and of stimulus intensity on electrodermal orienting response habituation, test response, and dishabituation. Subjects were 162 college students selected from a screening sample of 860 as representing extreme groups of high, medium, and low E crossing with high, medium, and low N. Subjects in all nine resulting groups were habituated to criterion on auditory stimuli of 60, 80, and 100 db. A novel (test) stimulus and a dishabituating standard stimulus followed criteron habituation at each intensity. Results indicated that response amplitude for initial, test, and dishabituation responses was a direct function and that habituation rate (trials-to-criterion) was an inverse function of stimulus intensity. Extraverts habituated more rapidly than introverts at high intensity and gave smaller test and dishabituation responses. Some results differed when regression coefficients defined habituation rate and when first stimulus intensities alone were examined. Correlations among initial, test, and dishabituation responses and between each of these and the two measures of habituation rate are also reported. Results were interpreted as partially supportive of Eysenck's theory.     

Long latency auditory evoked potentials

Experiment 1 elicited the P1, N1, P2, and N2 components of the long latency auditory evoked potential (AEP) using a 1000 Hz tone presented at 30, 50, or 70 dB SPL and 1-, 3-, or 5- second inter-stimulus intervals to assess the relative effects of the combination of these variables on component amplitude and latency. Four blocks of 16 tone presentations each were recorded from each subject to determine if changes in the AEP would occur because of short-term habituation. Both stimulus factors interacted significantly in a systematic fashion for the amplitude measures, with increases in latency also associated with increases in intensity and inter-stimulus interval. Only minor changes across the four trial blocks for either the amplitude or latency measures were observed over the various stimulus presentation conditions. Experiment 2 employed the same tone stimulus presented at 50 dB SPL and a 3-second inter-stimulus interval. Eight blocks of 64 trials were recorded from each subject on each day for four days to investigate long-term habituation effects. No substantial changes in any of the component amplitudes or latencies were obtained across the 32 trial blocks. It was concluded that intensity and inter-stimulus interval interact to determine AEP amplitude as well as latency values and that the constituent components do not change appreciably with repeated stimulus presentations, even after several days.     

Consciousness of attention and expectancy as reflected in event-related potentials and reaction times

The effects of conscious expectancies and attention on event-related potentials (ERP) and choice reaction times (RT) and their modulation by stimulus sequence were studied. Subjects retrospectively reported their expectancy of, and attention to, the terminal tones of short series. ERPs and RTs showed the usual sequential effects that were modulated by practice. As ratings were affected by only a few of the stimulus sequence, conscious access to sequence-based expectancy or attention appears to be fragmentary. Increased P300 amplitude with attention indicates conscious access to processing capacity. RTs and P300 latencies suggest stimulus processing time to decrease with sequence-based and consciously accessible expectancy. Differential effects of stimulus sequences and conscious expectancies on P300 amplitude indicate influences of two varieties of expectancy.     

Habituation and dishabituation of the electrodermal orienting reflex in relation to extraversion and neuroticism

Orienting reflex (OR) habituation and dishabituation may be influenced by individual difference variables, including Eysenck's Extraversion (E) and Neuroticism (N) dimensions. Ninety subjects formed nine groups based on the crossover of high, medium, and low E and N. Each subject received, at each of two auditory stimulus intensities, two blocks of tone presentations. The last standard stimulus trial was followed by a novel stimulus and four repetitions of the standard stimulus. Using square root SCR, extraverts showed smaller initial response amplitudes than introverts at the low intensity of stimulation, while the reverse was true at high intensity. E and N were unrelated to SCR habituation rate. However, extraverts showed no dishabituation, while introverts did dishabituate.     

Effects of telencephalic ablation on habituation of arousal responses, within and between daily training sessions in goldfish

Goldfish Carassius auratus were presented with a moving shadow stimulus at 2-min intervals and their cardiac and ventilatory responses were monitored. Normal fish, fish with their telencephalon ablated, and those with sham operations were compared for responsiveness and habituation to repeatedly presented stimuli over the 3-day test period. While all groups showed increased habituation on successive days testing, fish with their telencephalon ablated showed significantly slower response habituation within the daily test sessions when compared with the control groups. Subjects with their telencephalon ablated also showed a tendency for increased responsiveness on initial stimulus presentation and poorer retention between days of information relating to the eliciting test stimulus.     

Extraversion, attention, and habituation of the auditory evoked response

Short-term changes in the auditory evoked response to low-frequency tones (0.5 kHz, 80 dB) were examined for independent groups of introverts and extraverts under attend and ignore conditions. Introverts displayed greater N1-P2 amplitude than extraverts to the first stimulus in a four-stimulus train. The N1-P2 amplitude differences between introverts and extraverts could not be attributed to differences between the groups in either habituation or attention processes. Overall, the effect is indicative of the introverts' enhanced sensitivity to physical stimulation.     

Retention of bilateral performance as a function of practice order

The purpose of this study was to investigate the effect of practice order and initial performance hand on the bilateral retention of a simple tracking skill for 44 undergraduate volunteers. The apparatus was a Lafayette Model 30014 photoelectric rotary pursuit. The circle template was employed with rotation speed set at 20 rpm. Subjects were given 20-sec. trials and required to reach a criterion of 70% time on target twice in succession with both hands. For original practice, subjects were randomly assigned to one of four practice groups: preferred serial, non-preferred serial, preferred sequence and non-preferred sequence. Subjects' performance was recorded as the number of trials required to achieve criterion for both hands. One month later subjects were retested and scored in the same manner. A 2 X 2 X 2 analysis of variance with repeated measures on the last factor was used to determine the effects of initial hand, order of practice, testing periods, and the appropriate interactions. The results indicated that subjects' performance for the two testing periods differed significantly; retest was superior. Order of practice was significant and the sequential order more efficient during both learning and retest.     

Overextinction of the orienting reaction

Sokolov’s 1963 report of return of the orienting reaction (OR) to repeated stimulus presentations following habituation was examined in 18 S’s using the galvanic skin response (GSR) component of the OR and an auditory stimulus of 60 db intensity and 1000 cps. Both group and individual S data analysis indicated a return of the OR which habituated quickly. The number of stimulus presentations to the OR return point showed an inverse relationship to rate of initial OR habituation for individual S’s.     

正性情绪诱导下的自我参照加工：来自ERPs的证据

采用事件相关电位考察正性情绪对自我参照加工程度效应的影响。实验采用图片启动范式, 先呈现情绪图片, 然后再呈现自我参照刺激。实验发现, 在P2上, 中性情绪条件比正性情绪条件激发了更大的波幅, 高自我相关的刺激比其它刺激诱发了更短的P2潜伏期; 在N2上, 高自我相关名字比中等自我相关名字和非自我相关名字诱发了更小的N2的波幅和更长潜伏期; 在P3上, 高自我相关名字比中等自我相关名字和非自我相关名字诱发了更大的P3波幅, 中等自我相关名字比非自我相关名字诱发了更大的P3波幅。实验结果表明, 人类大脑对正性情绪刺激的加工可能是不敏感的。无论在正性情绪启动还是中性启动的影响下, 自我参照加工都能展现出稳定的特征, 而且高自我相关的刺激会得到更为深入和精细的加工, 表现出自我参照加工的程度效应。     

Multiple sources of positive- and negative-priming effects: An event-related potential study

Event-related potential correlates of positive priming (PP) and negative priming (NP) were investigated in order to further elucidate the cognitive mechanisms involved. Thirty-six participants performed both an identity- and a location-based priming task. Repeating the target stimulus/location from the immediately preceding display produced behavioral PP. With localization, but not with identification, behavioral NP was observed when the target stimulus/location matched the preceding distractor stimulus/location. Smaller P300 amplitude accompanied identity-based PP, suggesting persisting target-specific activation. The lateralized readiness potential, an index of correct/incorrect response activation, indicated persisting central motor activation as another source of PP. Both location-based PP and NP were accompanied by reduced P1/N1 and P300 amplitudes, pointing to the involvement of inhibition of return in location-based priming. The results support the view that multiple brain processes underlie behavioral priming.     

Heart-rate and electrodermal orienting responses to visual stimuli differing in complexity

Orienting response (OR) theory predicts that amount of information in the stimulus, or stimulus complexity, should be an important determinant of OR elicitation and habituation, more intense and more slowly habituating ORs being expected to complex than to simple stimuli. This prediction was tested in an experiment where subjects were exposed to simple and complex visual stimuli in randomized order, while heart-rate and skin conductance were measured. Complex stimuli evoked a more pronounced deceleratory heartrate response than did simple stimuli. However, the two conditions did not differ in rate of habituation of this response. For skin conductance responses, on the other hand, the complex stimulus took more trials than the simple stimulus to reach habituation, whereas the two conditions did not differ in response magnitude. Thus, the hypothesis of more intense orienting to complex stimuli was supported by the heart-rate data, and that of slower habituation to complex stimuli, of the skin conductance data.     

内隐序列学习与注意负荷关系的实验研究

采用2(注意负荷:高、低)单因素被试内实验设计,以18名在校大学生为被试,运用行为实验及事件相关电位技术,对内隐序列学习是否需要注意负荷的参与进行实验研究。结果发现:(1)在高、低注意负荷条件下都出现了内隐序列学习效应;(2)高注意负荷序列探测刺激诱发的P1、N1波幅显著大于低注意负荷序列探测刺激诱发的,表明高注意负荷条件下需要更多的注意;(3)高、低注意负荷序列内隐序列学习量差异不显著,表明内隐序列学习不受注意负荷影响。     

P300和CNV在GKT的延时反应范式中测谎效果的分离

在杀人游戏情境中,设置无反馈和有反馈两个实验组,采用GKT（guilt knowledge test）的延时反应范式,考察P300和CNV两种ERP成分的测谎效果。结果发现：刺激呈现后大约450ms诱发了一个正性ERP成分（P300）,大约800ms诱发了一个负性ERP成分（CNV）。在有、无反馈两种实验范式下,P300和CNV两种测谎指标的变化情况发生了分离——有无反馈不影响P300峰值大小;而在有反馈条件下,“杀手”对于犯罪细节词语（探测刺激）的CNV明显增大。使用Bootstrap波幅差异分析法,分别计算P300和CNV在有、无反馈情况下的检出率,结果发现：两个指标的检出率在有、无反馈两种实验范式下的变化情况也发生了分离。这些结果表明：P300和CNV两个指标具有不同的测谎功能,这可能和它们所反映的不同欺骗心理过程有关。     

Reliability of electrodermal habituation measures under two conditions of stimulus intensity

The present study investigated test-retest reliability of habituation of the evoked skin conductance response. Subjects received 20 presentations of a 1000-Hz, 3-sec tone at the same time of day on two separate occasions, separated by an interval of 97–160 days. Thirteen subjects received stimuli of 90 dB, while for 24 subjects, stimulus intensity was 70 dB. Interstimulus interval was 21 sec for both groups. Both absolute rate of habituation and trials to criterion displayed moderate reliability, and the relationships between habituation measures and other aspects of electrodermal activity were in agreement with previous findings.     

Elicitation and Inhibition of Competitive Fighting in Food Deprived Mice

Habituation as an index of the intrasensory and intersensory integration of form was investigated in nine-year-old children. In Habituation Period One, Ss were habituated to either a visual or a haptic 14″-perimeter standard stimulus. During Habituation Period Two, groups were subdivided and presented with one of the following stimuli: (a) 14″ visual, (b) 16″ visual, (c) 14″ haptic, or (d) 16″ haptic. The dependent variables were GSR frequency and amplitude, visual fixation time, and touching time. Subjects required more trials to habituate to the different stimulus presented in Habituation Period Two than Ss who received repeated presentations of the same stimulus. GSR frequency and amplitude habituated more consistently than did fixation and touching response measures. The results supported the use of the habituation paradigm for the study of intersensory and intrasensory integration, as well as providing support for extending Sokolov's theory to intersensory functions.     

Decision making and the P300 component of the cortical evoked response

The amplitude of P300, and of other components of the evoked potentials, was examined during a task which required Ss to make a response appropriate to the conjoint properties of two rapidly successive visual patterns. In one set of conditions, the task was structured such that both stimuli were needed for the choice judgment. In another set of conditions, the task was changed from choice to simple RT by presenting the patterns in a predictable order. It was observed that P300 was enhanced during the choice RT conditions and that this enhancement was present only for the P300 following the stimulus permitting the choice and not the other, relevant but not decisive, stimulus appearing in close temporal proximity. An appreciable degree of independence between P300 and other components was indicated by the appearance of P300 under conditions in which other evoked potential components were entirely refractory. The data support an account for P300 in terms of poststimulus processes, such as decision making, and not in terms of preparatory adjustments.     

内倾特质个体的自我参照加工程度效应

采用事件相关电位技术和三类刺激的经典oddball范式,以内隐的方式探讨内倾特质个体的自我参照加工程度效应及其神经机制。实验发现,在P2的波幅上,在电极前部、前中部和中部位置高自我相关的刺激比其它刺激诱发了更大的P2波幅。在P2的潜伏期上,在电极前部、中部、和中后部位置高自我相关的刺激比其它刺激诱发了更短的潜伏期。在N2的波幅上,高自我相关名字比其它刺激在左脑所诱发了更大的P2的波幅;对比内倾型被试,中间型被试的高自我相关名字比其它刺激诱发了更大的N2的波幅。在N2的潜伏期上,高自我相关的刺激在全脑都比其它刺激诱发了更短的N2潜伏期,且中后部电极位置的潜伏期最短;两类人格被试的高自我相关名字比其它刺激诱发了更短的N2潜伏期,但中间型人格被试的潜伏期最短。在P3平均波幅上,高自我相关的刺激在全脑都比其它刺激诱发了更大的P3波幅,其中中部脑区效应最大。研究结果表明内倾特质个体的自我参照加工具有程度效应,但对比中间型个体,内倾特质个体的自我参照加工的程度效应更弱。     

注视方向和面部表情对注意朝向的影响

摘 要 本文以三种表情面孔为材料,运用事件相关电位（ERP）方法探讨表情线索在注意朝向中与注视转移发生的交互及两者如何共同影响观察者的反应。结果发现：（1）线索效应在三种表情面孔的两种SOA中都出现了;（2）SOA较长时,注视线索效应量间的显著差异出现在中性和恐惧面孔、高兴和恐惧面孔间;（3）面部表情的效应出现在了表情线索诱发的P1成分上;（4）目标诱发的P1和N1说明了注视线索效应的存在及与表情间的交互。结论：表情线索先对观察者的朝向反应产生影响,随后是注视线索及其与表情线索发生的交互。