汉字识别中部件组合的频率效应

用整字识别、整合识别等任务研究部件组合频率在汉字识别中的作用。发现部件组合频率可促进高频两部件合体字的识别（实验一）;在先后呈现两组成部件时这种作用仍然存在（实验二）;但在识别高频三部件左右型合体字时（实验三）,位于左边的部件组合表现出易化作用（田型字）;位于右边的部件组合表现出干扰作用（田型字）。部件组合有与部件类似的频率效应。     

合成词加工中的词频、词素频率及语义透明度

通过变化汉语合成词的词素累积频率的方法,考察表面频率和语义透明度对加工速度的影响。研究发现,当控制透明度时,高表面频率词中存在词素累积频率效应,即词素频率越高反应越快;而在低表面频率词中没有。当控制表面频率,变化词素频率和透明度时,在透明词中,词素累积频率高的比低的加工快;但在不透明词中;这种反应趋势反转了：词素频率越高反应越慢。     

On the mean and variance of the tetrachoric correlation coefficient

Estimates of the mean and standard deviation of the tetrachoric correlation are compared with their expected values in several 2 × 2 tables. Significant bias in the mean is found when the minimum cell frequency is less than 5. Three formulas for the standard deviation are compared and guidelines given for their use.This research was performed when the first author was on leave at the University of California at Los Angeles and was supported in part by NIH Special Research Resources Grant RR-3. The second author was also supported by NIH Fellowship 5 F22 GM00328-02.     

Negative reinforcement with shock-frequency increase

Two avoidance-conditioning experiments in which responding delayed shocks are reported. Rats receiving an average of two shocks per minute (imposed condition) could produce, by pressing a bar, a 3-min alternate condition. Six (Experiment I) or more (Experiment II) shocks occurred in the alternate condition. All shocks in the alternate condition were delayed and delivered at 1-sec intervals. With long delays, all subjects produced the alternate condition and spent a large percentage of each session in the alternate condition. The first experiment demonstrated that the longer the delay from onset of the alternate condition to onset of the shocks, the more session time spent in the alternate condition. The second experiment indicated that despite increased shock frequency, behavior is acquired and maintained when responding leads to sufficient delay. Individual subjects produced the alternate condition by bar pressing in essentially one of two patterns. One pattern, termed postshock, involved bar pressing immediately after shock; the other, termed posttransition, involved responding immediately after the transition from the alternate to the imposed condition. These results indicate that shock-frequency reduction is not necessary for avoidance conditioning; delay to shock onset is sufficient.     

Behavior of humans in variable-interval schedules of reinforcement

During Phase I, human subjects pressed a button for monetary reinforcement in five variable-interval schedules, each of which specified a different frequency of reinforcement. The rate of responding was an increasing, negatively accelerated function of reinforcement frequency; the data conformed closely to Herrnstein's equation. During Phase II, the same five schedules were in operation, but in addition a concurrent variable-interval schedule (B) was introduced, responses on which were always reinforced at the same frequency. Response rate in component A increased while the response rate in B decreased, as a function of the reinforcement frequency in component A. Relative response rates in the two component schedules matched the relative frequencies of reinforcement. Comparing the absolute response rates in component A during Phase I and Phase II it was found that introduction of the concurrent schedule did not affect the value of the theoretical maximum response rate, but did increase the value of the reinforcement frequency needed to obtain any particular submaximal response rate.     

Integrated delays to shock as negative reinforcement

Rats were shocked at the rate of two per minute until they pressed a lever. In Experiment I, shocks were delivered at variable-time intervals averaging 30 sec; in Experiment II, shocks were delivered at fixed-time intervals of 30 sec. A response produced an alternate condition for a fixed-time period. The shock frequency following a response, calculated over the whole alternate condition, was two per minute. The pattern of shocks in the alternate condition was controlled so that the first shock occurred at the same time as it would have occurred had the response not been emitted; the remaining shocks were delayed until near the end of the alternate condition. Bar pressing was acquired in both experiments. This finding is not explained by two-factor theories of avoidance and is inconsistent with the notion that overall shock-frequency reduction is necessary for negative reinforcement. The data imply that responding is determined by the integrated delays to each shock following a response versus the integrated delays to shock in the absence of a response.     

Relationship between response rate and reinforcement frequency in variable-interval schedules: III. The effect of d-amphetamine.

Four rats were exposed to variable-interval schedules specifying a range of different reinforcement frequencies. The effects of two doses of d-amphetamine (1.6 and 3.2 mumol/kg) upon performance maintained under each schedule were examined. In the case of each rat, the response rates observed under control conditions (no injection or injection of the vehicle alone) were increasing, negatively accelerated functions of reinforcement frequency, the data conforming closely to Herrnstein's (1970) equation. In each rat, d-amphetamine (3.2 mumol/kg) significantly reduced the value of the constant Rmax, which expresses the theoretical maximum response rate. In each rat, the value of KH, which expresses the reinforcement frequency needed to obtain the half-maximal response rate, was also reduced, although this only achieved statistical significance in the case of one rat. When the proportional change in response rate in the presence of the drug was plotted against the response rate under control conditions on double logarithmic co-ordinates, linear functions of negative slope were obtained; in each rat the slope was steeper and the value of the control response rate at which d-amphetamine exerted no effect was lower in the case of the higher dose (3.2 mumol/kg) than in the case of the lower dose (1.6 mumol/kg).     

Warmup in free-operant avoidance as a function of the response-shock = shock-shock interval

Warmup effects, the repeated within-session transitions from ineffective to effective avoidance, were examined with rats on free-operant shock-delay procedures. The shock-shock and response-shock intervals were kept equal as they were varied. As measured by both response rates and shock rates, the magnitude of within-session change in performance was inversely related to the size of the manipulated intervals. The duration of warmup tended to decrease as the intervals were increased. This finding, that increased shock frequencies do not shorten the warmup, appears to be inconsistent with all interpretations of the warmup that have been offered to date. Late-session performances replicated general features of prior experiments, but differed with respect to details of secondary conclusions in previous reports. These differences may stem from the selection of especially proficient avoiders for previous experiments.     

Response requirements as constraints on output

Two experiments studied how added response requirements affected fixed-interval schedule performance. Experiment 1 involved tandem fixed-interval fixed-ratio schedules, and Experiment 2 studied conjunctive fixed-interval fixed-ratio schedules. In both, pigeons' output, defined as overall response rate or as responses during the interval, first increased and then decreased as the ratio was raised. With small ratio requirements, the frequency of reinforcement in time either did not change or decreased slightly. With progressively larger ratios, reinforcement frequency decreased consistently. Alternative explanations were discussed. The first, a reinforcement theory account, was that response strength is an increasing monotonic function of both the response requirement and reinforcement frequency, and the bitonic output function represents interacting effects. Increases in the response requirement accompanied by small changes in reinforcement frequency enhance output, but further increases result in large enough decrements in reinforcement frequency so that output is lowered. The second explanation does not view reinforcement as a basic process but, instead, derives from concepts of economics and conservation. Organisms allocate their behavior among alternatives so as to maximize value, where value is a function of the responses that can occur in a given situation under the set of restrictions imposed by particular schedules. One form of this theory explicitly predicts that output is a bitonic function of ratio requirements in simple ratio schedules. However, it was not clear that this model could explain the present effects involving joint ratio and interval schedule restrictions.     

字频影响常用汉字认知速度的实验研究

以熟知汉字的大学生为被试,对影响常用汉字认知速度的因素进行了探索．结果发现：（１）读音反应中存在字频效应,对高频字的认读明显快于低频字,表明字频是影响汉字认知速度的因素之一．（２）未见有笔画数效应,认读汉字不是以笔画为单位而可能是以意义化的组块为加工单位的．作者认为影响汉字认知速度的因素是多重的．