Confounds in pictorial sets: The role of complexity and familiarity in basic-level picture processing

Complexity is conventionally defined as the level of detail or intricacy contained within a picture. The study of complexity has received relatively little attention-in part, because of the absence of an acceptable metric. Traditionally, normative ratings of complexity have been based on human judgments. However, this study demonstrates that published norms for visual complexity are biased. Familiarity and learning influence the subjective complexity scores for nonsense shapes, with a significant training x familiarity interaction [F(1,52) = 17.53, p < .05]. Several image-processing techniques were explored as alternative measures of picture and image complexity. A perimeter detection measure correlates strongly with human judgments of the complexity of line drawings of real-world objects and nonsense shapes and captures some of the processes important in judgments of subjective complexity, while removing the bias due to familiarity effects.     

A caveat on the use of a revised bootstrap algorithm

A recently suggested revision of Efron's bootstrap algorithm for small bivariate samples discards bootstrap samples having fewer than 3 distinct points in order to prevent degeneracies in Pearson'sr. Examples are given showing that this approach may severely underestimate the variance of sample moments when sample sizes are very small. This paper should have appeared in the September 1984 issue, however, due to some unknown reason the final stages of the publication process were not completed. We regret any inconvenience to the authors and our readers.—Editors. This research was supported by NIMH grant number 37188.     

Multiple measures of hand-use lateralization in the ring-tailed lemur (Lemur catta)

Evaluated a free-ranging matriline of 13 ring-tailed lemurs (Lemur catta) from videotaped records for lateralized hand use with 2 tasks and 4 measures: food reaching, feeding posture, duration of food holding, and manipulation of food between mouth and hand while eating. Binomial z scores determined 7 lemurs to be left preferent in reaching, 3 right, and 3 ambipreferent. Ideographic analyses suggested possible sex-linked and early experience twin effects. When compared to right and ambipreferent lemurs, left reach preferent lemurs used the left hand more but bimanuals grasped less in food holding and also engaged in less hand-mouth food manipulation. The tendency to manipulate food was not correlated with bimanual holding but was inversely related to left hand holding and directly related to right hand holding. These patterns are discussed as possible precursors of human bimanual manipulation.     

Posturally related variations in the hand preferences of the ruffed lemur (Varecia variegata variegata)

The hand preferences of 5 semi-free-ranging black-and-white ruffed lemurs were assessed by using three distinct testing procedures. Testing conditions varied in the extent to which they required animals to make a whole body postural adjustment prior to making a reach. Minimal bodily adjustment was necessary for free foraging, whereas discrete food presentations on land (DFP-land) and in a moat (DFP-moat) promoted a gross reorientation of the animal's entire body. In the DFP-moat condition 4 animals exhibited exclusive use of the left hand, and only 1 of 515 reaches was made with the right hand. Similarly, all 5 animals showed a pronounced left hand preference in the DFP-land condition. The free-foraging condition revealed a hand preference for only 1 of the 5 subjects, and that preference was weak in comparison with those measured in the other two test conditions. These findings indicate that whole body postural adjustments critically influenced the expression of hand preference and should be taken into consideration in future studies of primate hand preferences.     

Predicting beauty: fractal dimension and visual complexity in art

Visual complexity has been known to be a significant predictor of preference for artistic works for some time. The first study reported here examines the extent to which perceived visual complexity in art can be successfully predicted using automated measures of complexity. Contrary to previous findings the most successful predictor of visual complexity was Gif compression. The second study examined the extent to which fractal dimension could account for judgments of perceived beauty. The fractal dimension measure accounts for more of the variance in judgments of perceived beauty in visual art than measures of visual complexity alone, particularly for abstract and natural images. Results also suggest that when colour is removed from an artistic image observers are unable to make meaningful judgments as to its beauty.     

Mapping the political language of the 1998 good friday agreement

The political statements of 12 prominent politicians involved in the 1998 Good Friday Agreement were examined using Diction (Hart, 1984a & 1995), a text analysis program that yields five measures of language variability: Optimism, Activity, Realism, Commonality, and Certainty. It was predicted that multi-dimensional scaling (MDS) would indicate that three of these variables could be used to group the politicians on the basis of their published policy positions. MDS indicated that the language of the politicians could be plotted on two dimensions. Activity, with an angle of 31.8°, and Optimism, with an angle of 35.9°, represent the first dimension. Realism loaded significantly on Dimension 2 which has an angle of 42.2°. Limitations of text analysis programs are considered together with suggestions for future developments.     

Dissociated backward priming effects in lexical decision and pronunciation tasks

Backward priming was examined at 150- and 500-msec prime-target stimulus onset asynchronies (SOAs) using visually presented primes and targets in lexical decision and pronunciation tasks. Two kinds of backward relations were used: compound items for which targets and primes formed a word in the backward direction (e.g., prime: HOP; target: bell), and noncompound items for which targets and primes did not form a word but were associatively related in the backward but not the forward direction (e.g., prime: BABY; target: stork). Results showed that backward priming effects were equivalent for compounds and noncompounds. However, for lexical decisions, backward priming occurred at both SOAs, whereas for pronunciation, it occurred only at the 150-msec SOA. We discuss how this SOA-dissociated backward priming effect in lexical decision and pronunciation tasks poses a serious challenge for all theories of semantic priming.     

The influence of negative advertising frames on political cynicism and politician accountability

This research examined the influence of negative political advertising frames on the thoughts and feelings people generate in response to campaign advertising. Preparing and conducting this investigation involved the use of a multiple‐method strategy. Content analysis identified two advertising frames (i.e., candidate theme and ad hoc issue advertisements) and two experiments separately induced political cynicism and politician accountability. Three hundred and sixty people participated in the experimental studies, in which they read and responded, using a thought‐listing technique, to candidate theme or ad hoc issue negative advertisements. Results demonstrated that participants were more likely to generate cynical comments and hold politicians accountable for the country's ills when reading candidate theme advertisements than ad hoc issue advertisements. The results indicate that this contributes to a political climate of cynicism and may function to erode the electorate's overall trust in government.     

Multiple measures of motor lateralization in human primates (Homo sapiens)

Laterality was assessed in 100 human (Homo sapiens) subjects through the use of five measures of motoric behavior in three categories: locomotor, manual, postural. Locomotor measures included leading limb for initiation of walking and whole-body turning. Performance and questionnaire measures were used to assess lateral hand bias. Postural bias was assessed as the weight distribution in quiet standing. Population-level biases on the manual and leading limb measures were to the right; on posture and turning, to the left. Locomotor measures were found to be altered by marching experience. Only the manual measures were correlated. We compare the results with those of nonhuman primate studies that have used similar measures and discuss some patterns of laterality common to human and nonhuman primates.     

Characteristics of life events during adolescence

Two studies of the characteristics of life events during adolescence are reported. In the first, open-ended reports of major life events and daily events were obtained from early, middle, and late adolescents. Analyses of the frequency of past events perceived as positive versus negative revealed effects for type of event (major vs. daily), age, and gender. In contrast, anticipated events were perceived similarly across age and gender. The second study examined judgments by older adolescents of the valence, type, and domain of life events. Consensus regarding these characteristics was achieved on only a small portion of events. The implications of these findings for the measurement of life events during adolescence are highlighted.