Tracking hierarchical processing in morphological decomposition with brain potentials

One important debate in psycholinguistics concerns the nature of morphological decomposition processes in visual word recognition (e.g., darkness = {dark} + {-ness}). One theory claims that these processes arise during orthographic analysis and prior to accessing meaning (Rastle & Davis, 2008), and another argues that these processes arise through greater temporal overlap between the activation of orthographic and semantic information (Feldman, O'Connor, & Moscoso del Prado Martín, 2009). This issue has been the subject of intense debate in studies using masked priming but has yet to be resolved unequivocally. The present study takes another approach to resolving this controversy by examining brain potentials as participants made lexical decisions to unprimed morphological (darkness), pseudomorphological (corner), and nonmorphological (brothel) stimuli. Results revealed a difference from ～190 ms between the nonmorphological condition and the other 2 conditions (which showed no differentiation), a likely correlate of morphological processing reliant exclusively on orthography. Only 60-70 ms later was there evidence of the activation of semantic information, when the pseudomorphological condition diverged from the other 2 conditions. These results provide unambiguous support for a hierarchical model of morphological processing whereby decomposition is based initially on orthographic analysis and is only later constrained by semantic information. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

A new look at social attention: Orienting to the eyes is not (entirely) under volitional control

People tend to look at other people's eyes, but whether this bias is automatic or volitional is unclear. To discriminate between these two possibilities, we used a "don't look" (DL) paradigm. Participants looked at a series of upright or inverted faces, and were asked either to freely view the faces or to avoid looking at the eyes, or as a control, the mouth. As previously demonstrated, participants showed a bias to attend to both eyes and mouths during free viewing. In the DL condition, participants told to avoid the eyes of upright faces were unable to fully suppress the tendency to fixate on the faces' eyes, whereas participants told to avoid the mouth of upright faces successfully eliminated their bias to overtly attend to that feature. When faces were inverted, participants were equally able to suppress looks to the eyes and mouth. Together, these results suggest that the tendency to look at the eyes reflects orienting that is both volitional and automatic, and that the engagement of holistic or configural face processing mechanisms during upright face viewing has an influence in guiding gaze automatically to the eyes. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

Rapid activation of motor responses by illusory contours

Whereas physiological studies indicate that illusory contours (ICs) are signaled in early visual areas at short latencies, behavioral studies are divided as to whether IC processing can proceed in a fast, automatic, bottom-up manner or whether it requires extensive top-down intracortical feedback or even awareness and cognition. Here, we employ a response priming paradigm to assess two measures of IC processing using identical stimuli: response priming by ICs, which can occur independently of visual awareness, and a measure of visual awareness of the ICs. In three experiments, participants responded to the orientation of illusory and real-contour targets preceded by illusory and real-contour primes at stimulus-onset asynchronies from 35 to 106 ms. Both illusory and real-contour targets were strongly primed by ICs, and this effect was independent of prime visibility. The effect was fully present in the fastest responses and cannot be explained by responses to stimulus features other than the ICs. Results indicate that ICs, regardless of whether they are consciously perceived, activate fast motor responses, indicating that they are processed without time-consuming intracortical feedback. We conclude that conflicting studies were based on qualitatively different measures of IC processing, some depending on visual awareness and others independent of it. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

Time- and space-order effects in timed discrimination of brightness and size of paired visual stimuli

Despite the importance of both response probability and response time for testing models of choice, there is a dearth of chronometric studies examining systematic asymmetries that occur over time- and space-orders in the method of paired comparisons. In this study, systematic asymmetries in discriminating the magnitude of paired visual stimuli are examined by way of log odds ratios of binary responses as well as by signed response speed. Hierarchical Bayesian modeling is used to map response probabilities and response speed onto constituent psychological process, and processing capacity is also assessed using response time distribution hazard functions. The findings include characteristic order effects that change systematically in magnitude and direction with changes in the magnitude and separation of the stimuli. After Hellstr?m (1979, 2000), sensation weighting (SW) model analyses show that such order effects are reflected in the weighted accumulation of noisy information about the difference between stimulus values over time, and interindividual differences in weightings asymmetries are related to the relative processing capacity of participants. An account of SW based on the use of reference level information and maximization of signal-to-noise ratios is posited, which finds support from theoretically driven analyses of behavioral data.     

Eye gaze versus arrows as spatial cues: two qualitatively different modes of attentional selection

This study aimed to evaluate the type of attentional selection (location- and/or object-based) triggered by two different types of central noninformative cues: eye gaze and arrows. Two rectangular objects were presented in the visual field, and subjects' attention was directed to the end of a rectangle via the observation of noninformative directional arrows or eye gaze. Similar experiments with peripheral cues have shown an object-based effect: faster target identification when the target is presented on the cued object as compared to the uncued object, even when the distance between target and cue was the same. The three reported experiments aimed to compare the location- and object-based attentional orienting observed with arrows and eye gaze, in order to dissociate the orienting mechanisms underlying the two types of orienting cues. Results showed similar cueing effects on the cued versus oppositely cued locations for the two cue types, replicating several studies with nonpredictive gaze and arrow cues. However, a pure object-based effect occurred only when an arrow cue was presented, whereas a pure location-based effect was only found for eye-gaze cues. It is suggested that attention is nonspecifically directed to nearby objects when a noninformative arrow is used as cue, whereas it is selectively directed to a specific cued location when noninformative eye gaze is used. This may be mediated by theory of mind mechanisms.     

Cue and target processing modulate the onset of inhibition of return

Inhibition of return (IOR) is modulated by task set and appears later in discrimination tasks than in detection tasks. Several hypotheses have been suggested to account for this difference. We tested three of these hypotheses in two experiments by examining the influence of cue and target level of processing on the onset of IOR. In the first experiment, participants were required to respond to both the cue and target. The pattern of results showed that deeper processing of the cue or target advanced the onset of IOR. In the second experiment, participants were not required to respond to the cue and a reverse pattern of results emerged, which replicated the general findings in cuing tasks. We conclude that in more-demanding tasks, an additional process slows down the processing of a nonpredictive cue in order to enhance the processing of the target.     

In medio stat virtus: theoretical and methodological extremes regarding reciprocity will not explain complex social behaviors

Guala contests the validity of strong reciprocity as a key element in shaping social behavior by contrasting evidence from experimental games to that of natural and historic data. He suggests that in order to understand the evolution of social behavior researchers should focus on natural data and weak reciprocity. We disagree with Guala's proposal to shift the focus of the study from one extreme of the spectrum (strong reciprocity) to the other extreme (weak reciprocity). We argue that the study of the evolution of social behavior must be comparative in nature, and we point out experimental evidence that shows that social behavior is not cooperation determined by a set of fixed factors. We argue for a model that sees social behavior as a dynamic interaction of genetic and environmental factors.     

Towards a unified theory of reciprocity

In a unified theory of human reciprocity, the strong and weak forms are similar because neither is biologically altruistic and both require normative motivation to support cooperation. However, strong reciprocity is necessary to support cooperation in public goods games. It involves inflicting costs on defectors; and though the costs for punishers are recouped, recouping costs requires complex institutions that would not have emerged if weak reciprocity had been enough.     

The distribution of fixation durations during reading: effects of stimulus quality

Participants' eye movements were recorded as they read single sentences presented normally, presented entirely in faint text, or presented normally except for a single faint word. Fixations were longer when the entire sentence was faint than when the sentence was presented normally. In addition, fixations were much longer on a single faint word embedded in normal text, compared to when the entire sentence was faint. The primary aim of the study was to examine the influence of stimulus quality on the distribution of fixation durations. Ex-Gaussian fitting revealed that stimulus quality affected the mean of the Normal component, but in contrast to results from single-word tasks (Plourde & Besner, 1997), stimulus quality did not affect the exponential component, regardless of whether one or all words were faint. The results also contrast with the finding (Staub, White, Drieghe, Hollway, & Rayner, 2010) that the word frequency effect on fixation durations is an effect on both of the critical distributional parameters. These findings are argued to have implications for the interpretation of the role of stimulus quality in word recognition, and for models of eye movement control in reading.     

Neuronal deactivation is equally important for understanding emotional processing

In their analyses of the neural correlates of discrete emotionality, Lindquist et al. do not consider the numerous drawbacks to inferring psychological processes based on currently available cognitive neurometric technology. The authors also disproportionately emphasize the relevance of neuronal activation over deactivation, which, in our opinion, limits the scope and utility of their conclusions.