Sequential evaluation of behavioral treatments and methylphenidate dosage for children with attention deficit hyperactivity disorder

We used a sequential approach to evaluate the relative and combined effects of different types of behavioral treatments, as well as dosage of methylphenidate (MPH), on the disruptive behavior of 3 students who had been diagnosed with attention deficit hyperactivity disorder. Results showed that individualized behavioral treatments produced decreases in disruptive behavior equivalent to MPH for all 3 participants and demonstrated the need to evaluate behavioral treatments and medication dosage on an individual basis.     

The effects of road traffic noise and meaningful irrelevant speech on different memory systems

To explore why noise has reliable effects on delayed recall in a certain text-reading task, this episodic memory task was employed with other memory tests in a study of road traffic noise and meaningful but irrelevant speech. Context-dependent memory was tested and self-reports of affect were taken. Participants were 96 high school students. The results showed that both road traffic noise and meaningful irrelevant speech impaired recall of the text. Retrieval in noise from semantic memory was also impaired. Attention was impaired by both noise sources, but attention did not mediate the noise effects on episodic memory. Recognition was not affected by noise. Context-dependent memory was not shown. The lack of mediation by attention, and road traffic noise being as harmful as meaningful irrelevant speech, are discussed in relation to where in the input/storing/output sequence noise has its effect and what the distinctive feature of the disturbing noise is.     

Global and local covert visual attention: Evidence from a bayesian hidden markov model

Psychological, psychophysical and physiological research indicates that people switch between two covert attention states, local and global attention, while visually exploring complex scenes. The focus in the local attention state is on specific aspects and details of the scene, and on examining its content with greater visual detail. The focus in the global attention state is on exploring the informative and perceptually salient areas of the scene, and possibly on integrating the information contained therein. The existence of these two visual attention states, their relative prevalence and sequence in time has remained empirically untested to date. To fill this gap, we develop a psychometric model of visual covert attention that extends recent work on hidden Markov models, and we test it using eye-movement data. The model aims to describe the observed time series of saccades typically collected in eye-movement research by assuming a latent Markov process, indicative of the brain switching between global and local covert attention. We allow subjects to be in either state while exploring a stimulus visually, and to switch between them an arbitrary number of times. We relax the no-memory-property of the Markov chain. The model that we develop is estimated with MCMC methodology and calibrated on eye-movement data collected in a study of consumers' attention to print advertisements in magazines.We thank Dominique Claessens of Verify International for making the data available to us.     

Deficit in selective and divided attention associated with cholinergic basal forebrain immunotoxic lesion produced by 192-saporin; motoric/sensory deficit associated with Purkinje cell immunotoxic lesion produced by OX7-saporin

The immunotoxin 192-saporin, infused intracerebroventricularly into rats, destroys cholinergic neurons in the basal forebrain nuclei. Doses required for complete cholinergic loss also kill some Purkinje cells. The immunotoxin OX7-saporin, when infused intraventricularly into rats, destroys Purkinje cells in a pattern similar to that produced by 192-saporin, without affecting cholinergic neurons. Thus, we used OX7-saporin to distinguish behavioral effects of 192-saporin due to cerebellar damage versus those due to cholinergic cell loss. Three doses of 192-saporin (1.6, 2.6, and 3.3 micrograms/rat) were chosen along with a dose of OX7-saporin (2.0 micrograms/rat) that produced Purkinje loss equivalent to the two highest doses of 192-saporin. Groups of Fischer-344 rats were trained in the multiple choice reaction time task and retested with more complex tasks after lesioning. They were also tested in the water maze, passive avoidance, acoustic startle, and open field. The OX7-saporin group exhibited changes in many tests suggesting hypermotility and sensory deficits. The 192-saporin groups differed from the OX7-saporin group when they displayed deficits in multiple choice reaction time tasks in which novel challenges were introduced, including sessions with a noise distractor, shortened and lengthened intertrial intervals, and use of nine instead of five sources of light stimulus. The 192-saporin groups showed no impairment in the other tasks. The cholinergic basal forebrain lesion may mask some of the effects of cerebellar damage up to a threshold after which effects of Purkinje cell loss predominate when 192-saporin is administered intraventricularly.     

Infant responses to adult happy and sad vocal and facial expressions during face-to-face interactions

We examined 5-month-olds’ responses to adult facial versus vocal displays of happy and sad expressions during face-to-face social interactions in three experiments. Infants interacted with adults in either happy-sad-happy or happy-happy-happy sequences. Across experiments, either facial expressions were present while presence/absence of vocal expressions was manipulated or visual access to facial expressions was blocked but vocal expressions were present throughout. Both visual attention and infant affect were recorded. Although infants looked more when vocal expressions were present, they smiled significantly more to happy than to sad facial expressions regardless of presence or absence of the voice. In contrast, infants showed no evidence of differential responding to voices when faces were obscured; their smiling and visual attention simply declined over time. These results extend findings from non-social contexts to social interactions and also indicate that infants may require facial expressions to be present to discriminate among adult vocal expressions of affect.     

Four empirical tests of Unconscious Thought Theory

According to Unconscious Thought Theory, people make better decisions after unconscious than after conscious thought (Dijksterhuis, Bos, Nordgren, & van Baaren, 2006a). Unconscious Thought Theory yields four specific predictions. First, an exact replication of Dijksterhuis et al. (2006a) study should indicate that unconscious decisions are superior to conscious decisions. Second, decisions should improve with duration of conscious thought. Third, unconscious decisions should be superior to conscious decisions, even if unconscious decisions are deliberated while having access to information. Fourth, unconscious decisions should be based on a weighting strategy. We report results of four studies, featuring 480 participants, that yield no evidence in favor of these predictions. Therefore our findings cast doubt on Unconscious Thought Theory and its advice to base decisions on unconscious thought. The results of our studies suggest that it is better to base decisions on conscious thought while having access to information.     

视觉刺激探测的警觉性注意特征初探

采用"预警提示-目标探测"范式,对视觉刺激探测的警觉性注意特征进行初步探索。实验一表明,随着预备到目标刺激的时间间隔(interstimulus interval,ISI)变化,固定位置上探测目标刺激的速度也随之变化,并且对大概率刺激的探测更快,表现出了警觉性注意的稳定性和选择性特征。实验二进一步考察了目标刺激在不同ISI和不同空间位置的情况,除发现与实验一相似的结果以外,被试探测目标刺激的速度随注意视角增大而下降,表现出了警觉性注意的集中性特征。     

The Role of Executive Control of Attention and Selective Encoding for Preschoolers' Learning

Selectivity in encoding, aspects of attentional control and their contribution to learning performance were explored in a sample of preschoolers. While the children are performing a learning task, their encoding of relevant and attention towards irrelevant information was recorded through an eye‐tracking device. Recognition of target items was used as measure of learning outcome, and individual differences in resistance to interference and inhibition of attention to task‐irrelevant stimuli (i.e. distractibility) were used as measures of executive control of attention. Results indicated well‐developed selectivity during encoding in young children. Recognition performance was related to selective encoding and aspects of attentional control, explaining individual differences in learning. Copyright © 2011 John Wiley & Sons, Ltd.     

Perceiving a story outside of conscious awareness: When we infer narrative attributes from subliminal sequential stimuli

Perceiving a story behind successive movements plays an important role in our lives. From a general perspective, such higher mental activity would seem to depend on conscious processes. Using a subliminal priming paradigm, we demonstrated that such story perception occurs without conscious awareness. In the experiments, participants were subliminally presented with sequential pictures that represented a story in which one geometrical figure was chased by the other figure, and in which one fictitious character defeated the other character in a tug-of-war. Although the participants could not report having seen the pictures, their automatic mental associations (i.e., associations that are activated unintentionally, difficult to control, and not necessarily endorsed at a conscious level) were shifted to line up with the story. The results suggest that story perception operates outside of conscious awareness. Implications for research on the unconscious were also briefly discussed.     

Acquisition of social referencing via discrimination training in infants

This experiment investigated social referencing as a form of discriminative learning in which maternal facial expressions signaled the consequences of the infant's behavior in an ambiguous context. Eleven 4- and 5-month-old infants and their mothers participated in a discrimination-training procedure using an ABAB design. Different consequences followed infants' reaching toward an unfamiliar object depending on the particular maternal facial expression. During the training phases, a joyful facial expression signaled positive reinforcement for the infant reaching for an ambiguous object, whereas a fearful expression signaled aversive stimulation for the same response. Baseline and extinction conditions were implemented as controls. Mothers' expressions acquired control over infants' approach behavior for all participants. All participants ceased to show discriminated responding during the extinction phase. The results suggest that 4- and 5-month-old infants can learn social referencing via discrimination training.