Stroop interference is a composite phenomenon: Evidence from distinct developmental trajectories of its components

Only one previous developmental study of Stroop task performance (Schiller, 1966) has controlled for differences in processing speed that exist both within and between age groups. Therefore, the question of whether the early developmental change in the magnitude of Stroop interference actually persists after controlling for processing speed needs further investigation; work that is further motivated by the possibility that any remaining differences would be caused by process(es) other than processing speed. Analysis of data from two experiments revealed that, even after controlling for processing speed using z‐transformed reaction times, early developmental change persists such that the magnitude of overall Stroop interference is larger in 3rd‐ and 5th graders as compared to 1st graders. This pattern indicates that the magnitude of overall Stroop interference peaks after 2 or 3 years of reading practice (Schadler & Thissen, 1981). Furthermore, this peak is shown to be due to distinct components of Stroop interference (resulting from specific conflicts) progressively falling into place. Experiment 2 revealed that the change in the magnitude of Stroop interference specifically results from joint contributions of task, semantic and response conflicts in 3rd‐ and 5th graders as compared to a sole contribution of task conflict in 1st graders. The specific developmental trajectories of different conflicts presented in the present work provide unique evidence for multiple loci of Stroop interference in the processing stream (respectively task, semantic and response conflict) as opposed to a single (i.e. response) locus predicted by historically – favored response competition accounts.     

Developmental and content effects in reasoning with causal conditionals

Two predictions derived from Markovits and Barrouillet's (2001) developmental model of conditional reasoning were tested in a study in which 72 twelve-year-olds, 80 fifteen-year-olds, and 104 adults received a paper-and-pencil test of conditional reasoning with causal premises ("if cause P then effect Q"). First, we predicted that conditional premises would induce more correct uncertainty responses to the Affirmation of the consequent and Denial of the antecedent forms when the antecedent term is weakly associated to the consequent than when the two are strongly associated and that this effect would decrease with age. Second, uncertainty responding to the Denial of the antecedent form ("P is not true") should be easier when the formulation of the minor premise invites retrieval of alternate antecedents ("if something other than P is true"). The results were consistent with the hypotheses and indicate the importance of retrieval processes in understanding developmental patterns in conditional reasoning with familiar premises.     

Lateralization of narrow-band noise by blind and sighted listeners

The effects of varying interaural time delay (ITD) and interaural intensity difference (IID) were measured in normal-hearing sighted and congenitally blind subjects as a function of eleven frequencies and at sound pressure levels of 70 and 90 dB, and at a sensation level of 25 dB (sensation level refers to the pressure level of the sound above its threshold for the individual subject). Using an 'acoustic' pointing paradigm, the subject varied the IID of a 500 Hz narrow-band (100 Hz) noise (the 'pointer') to coincide with the apparent lateral position of a 'target' ITD stimulus. ITDs of 0, +/-200, and +/-400 micros were obtained through total waveform delays of narrow-band noise, including envelope and fine structure. For both groups, the results of this experiment confirm the traditional view of binaural hearing for like stimuli: non-zero ITDs produce little perceived lateral displacement away from 0 IID at frequencies above 1250 Hz. To the extent that greater magnitude of lateralization for a given ITD, presentation level, and center frequency can be equated with superior localization abilities, blind listeners appear at least comparable and even somewhat better than sighted subjects, especially when attending to signals in the periphery. The present findings suggest that blind listeners are fully able to utilize the cues for spatial hearing, and that vision is not a mandatory prerequisite for the calibration of human spatial hearing.     

Shepherd Ivory Franz: His contributions to neuropsychology and rehabilitation

Shepherd I. Franz was an important figure in psychology of the last century, and historians of psychology have given recognition to much of his work. However, his experimental work with animals and his pioneer investigations in experimental and clinical neuropsychology have been largely ignored. This article reviews his conceptual, assessment, and treatment contributions, including (1) his pioneering work on the use of learned behavior as a baseline for the study of cerebral ablations, (2) his interest in brain plasticity, (3) his development of comprehensive psychological assessment methods, and (4) his work on the rehabilitation of neurological patients with techniques derived from his animal experiments. His work predated much of what is now part of the conceptual substance of the experimental and clinical neurosciences.     

Selective influence of second target exposure duration and Task1 load effects in the attentional blink phenomenon

The purpose of the experiments was to constrain the locus of interference in the attentional blink (AB) paradigm. Two visual stimuli, T₁ and T₂, were shown 300 msec apart, and each was followed by a mask. T₁ was an “H,” an “S,” an “ &, ” or a blank field; T₂ consisted of five letters. In Task₁, blank fields and & characters could be ignored, whereas Hs and Ss had to be identified and reported. Task₂ was always to report as many letters as possible from T₂. Task₂ performance was lower when T₁ had to be reported, as expected from the attentional blink phenomenon (AB). The exposure duration of T₂ was also manipulated. More letters could be reported as exposure duration was increased. However, this effect was additive with manipulations of Task₁ processing load that produced the AB effect. Log-linear analyses assuming that effects of T₂ exposure duration and Task₁ load effects occur at functionally distinct stages of processing provided satisfactory fits to the results, suggesting that none of the AB effect occurs as early as those of T₂ exposure duration. The results suggest that the locus of the AB effect is later than the stage(s) of processing affected by exposure duration.     

Scholastic achievement of adolescent refugees from Cambodia and Central America

This study investigated the relationship of emotional disturbance and pre- and postmigration environment to the scholastic achievement of adolescent refugees of very different cultural backgrounds. One hundred fifty-two Central American and Cambodian students in six Canadian high schools, as well as their parents, were interviewed to assess the students' emotional problems (using the Youth Self-Report and Child Behavior Checklist) and to determine the pre- and postmigration family environment. The findings indicated that the relationship between the emotional problems and scholastic achievement of teenaged refugees was tenuous. It was concluded that a connection between young refugees' symptomatology and their functional capacity should not be assumed. Nonetheless, certain pre- and postmigration variables, particularly trauma experienced in the homeland, seem to be associated with the academic achievement of some refugees.     

Stress, self-esteem, and suicidal ideation in late adolescents

The relationships among stress, self-esteem, and suicidal ideation in late adolescents were examined in a group of college students. Multiple regression analysis indicated that both stress and self-esteem were significantly related to suicidal ideation; low self-esteem and stressful life events significantly predicted suicidal ideation. The hypothesis that self-esteem would moderate the effects of life stressors on suicidal ideation was supported at the .06 level. A significant minority of the sample indicated having thoughts severe enough to be classified as clinical suicidal ideation. In general, participants who had experienced negative life events in the 6 to 12 months prior to participating in the study had lower self-esteem than those who had similar stresses within the prior six months. However, the opposite was true for clinical suicidal ideators; those who experienced negative life stressors recently had lower self-esteem than those who experienced negative life events six months to a year in the past.     

How do speakers avoid ambiguous linguistic expressions?

Three experiments assessed how speakers avoid linguistically and nonlinguistically ambiguous expressions. Speakers described target objects (a flying mammal, bat) in contexts including foil objects that caused linguistic (a baseball bat) and nonlinguistic (a larger flying mammal) ambiguity. Speakers sometimes avoided linguistic-ambiguity, and they did so equally regardless of whether they also were about to describe foils. This suggests that comprehension processes can sometimes detect linguistic-ambiguity before producing it. However, once produced, speakers consistently avoided using the same linguistically ambiguous expression again for a different meaning. This suggests that production processes can successfully detect linguistic-ambiguity after-the-fact. Speakers almost always avoided nonlinguistic-ambiguity. Thus, production processes are especially sensitive to nonlinguistic- but not linguistic-ambiguity, with the latter avoided consistently only once it is already articulated.     

Effects of modeling and topic stimulus on self-referent touching

Self-touching is defined as self-directed touches, e.g., scratching or rubbing, that have no apparent conscious motivation. Earlier research on self-touching focused on internal processes associated with self-touching, e.g., mental conflict, while more recent research has considered external motivators, such as an auditory or visual presentation of a provocative stimulus, e.g., leeches. Here, 110 undergraduate psychology students (68 women, 42 men; M age = 18.7 yr., SD = 1.0) were shown a video about chiggers to replicate previous findings, while simultaneously studying the social influence of self-touching modeled by the presenter. A significant interaction was found as modeled self-touching significantly increased participants' self-touching when they were also attending to the video about chiggers. The results are discussed in terms of potential processes underlying this behavior and directions for research.