Anterior cingulate cortex and cognitive control: Neuropsychological and electrophysiological findings in two patients with lesions to dorsomedial prefrontal cortex

Whereas neuroimaging studies of healthy subjects have demonstrated an association between the anterior cingulate cortex (ACC) and cognitive control functions, including response monitoring and error detection, lesion studies are sparse and have produced mixed results. Due to largely normal behavioral test results in two patients with medial prefrontal lesions, a hypothesis has been advanced claiming that the ACC is not involved in cognitive operations. In the current study, two comparably rare patients with unilateral lesions to dorsal medial prefrontal cortex (MPFC) encompassing the ACC were assessed with neuropsychological tests as well as Event-Related Potentials in two experimental paradigms known to engage prefrontal cortex (PFC). These included an auditory Novelty Oddball task and a visual Stop-signal task. Both patients performed normally on the Stroop test but showed reduced performance on tests of learning and memory. Moreover, altered attentional control was reflected in a diminished Novelty P3, whereas the posterior P3b to target stimuli was present in both patients. The error-related negativity, which has been hypothesized to be generated in the ACC, was present in both patients, but alterations of inhibitory behavior were observed. Although interpretative caution is generally called for in single case studies, and the fact that the lesions extended outside the ACC, the findings nevertheless suggest a role for MPFC in cognitive control that is not restricted to error monitoring.     

Age differences in neural activity related to mentalizing during person perception

ABSTRACT

Mentalizing, or thinking about others’ mental states, shapes social interactions. Older adults (OA) have reduced mentalizing capacities reflected by lower medial prefrontal cortex (mPFC) activation. The current study assessed if OA’ lower mPFC activation reflects less spontaneous mentalizing during person perception. Younger adults (YA) and OA viewed ingroup White and outgroup Black and Asian faces and completed a mentalizing task during fMRI. Afterward, they completed a task in which they inferred mental states from faces. Using an mPFC region defined by the mentalizing task, OA had lower activity than YA during person perception. OA’ mPFC activity toward faces positively related to their mentalizing outside the scanner. The extent of OA’ lower mPFC activation during person perception may depend on their actual detection of mental states in faces. Further, YA’, but not OA’, mPFC activity distinguished between outgroups. OA’ lower mentalizing-related mPFC activity may reduce their ability to individuate outgroup members.     

Numbsense of shape,texture, and objects after left parietal infarction: A case report

Numbsense is a phenomenon, wherein patients can correctly respond to somatosensory stimuli at a higher rate than expected by chance, but cannot perceive the same stimuli consciously. Previously, numbsense has been reported in tactile localization of stimuli on the patient’s own body. Here, we describe a patient with numbsense that involved touched objects. The patient could not recognize the majority of somatosensory stimuli after left parietal infarction, but could correctly select shape, texture, and object stimuli more frequently than expected by chance.     

Random word generation reveals spatial encoding of syllabic word length

Existing random number generation studies demonstrate the presence of an embodied attentional bias in spontaneous number production corresponding to the horizontal Mental Number Line: Larger numbers are produced on right-hand turns and smaller numbers on left-hand turns (Loetscher et al.,2008, Curr. Biol., 18, R60). Furthermore, other concepts were also shown to rely on horizontal attentional displacement (Di Bono and Zorzi, 2013, Quart. J. Exp. Psychol., 66, 2348). In two experiments, we used a novel random word generation paradigm combined with two different ways to orient attention in horizontal space: Participants randomly generated words on left and right head turns (Experiment 1) or following left and right key presses (Experiment 2). In both studies, syllabically longer words were generated on right-hand head turns and following right key strokes. Importantly, variables related to semantic magnitude or cardinality (whether the generated words were plural-marked, referred to uncountable concepts, or were associated with largeness) were not affected by lateral manipulations. We discuss our data in terms of the ATOM (Walsh, 2015, The Oxford handbook of numerical cognition, 552) which suggests a general magnitude mechanism shared by different conceptual domains.     

Preliminary evidence for selective cortical responses to music in one-month-old infants

Prior studies have observed selective neural responses in the adult human auditory cortex to music and speech that cannot be explained by the differing lower-level acoustic properties of these stimuli. Does infant cortex exhibit similarly selective responses to music and speech shortly after birth? To answer this question, we attempted to collect functional magnetic resonance imaging (fMRI) data from 45 sleeping infants (2.0- to 11.9-weeks-old) while they listened to monophonic instrumental lullabies and infant-directed speech produced by a mother. To match acoustic variation between music and speech sounds we (1) recorded music from instruments that had a similar spectral range as female infant-directed speech, (2) used a novel excitation-matching algorithm to match the cochleagrams of music and speech stimuli, and (3) synthesized “model-matched” stimuli that were matched in spectrotemporal modulation statistics to (yet perceptually distinct from) music or speech. Of the 36 infants we collected usable data from, 19 had significant activations to sounds overall compared to scanner noise. From these infants, we observed a set of voxels in non-primary auditory cortex (NPAC) but not in Heschl's Gyrus that responded significantly more to music than to each of the other three stimulus types (but not significantly more strongly than to the background scanner noise). In contrast, our planned analyses did not reveal voxels in NPAC that responded more to speech than to model-matched speech, although other unplanned analyses did. These preliminary findings suggest that music selectivity arises within the first month of life. A video abstract of this article can be viewed at https://youtu.be/c8IGFvzxudk .

Research Highlights

• Responses to music, speech, and control sounds matched for the spectrotemporal modulation-statistics of each sound were measured from 2- to 11-week-old sleeping infants using fMRI.
• Auditory cortex was significantly activated by these stimuli in 19 out of 36 sleeping infants.
• Selective responses to music compared to the three other stimulus classes were found in non-primary auditory cortex but not in nearby Heschl's Gyrus.
• Selective responses to speech were not observed in planned analyses but were observed in unplanned, exploratory analyses.

     

Would a neuroscience of violence aid in understanding legal culpability?

Defense attorneys in criminal cases are beginning to argue that their clients were biologically predisposed to committing their crimes and therefore were less responsible for their behavior. Indeed, if our brains cause our behavior, and our brains are the way they are because of genetic composition, insults, disease, and life experiences, it becomes difficult to argue that any punishment as justified retribution for behavior is cogent. In this essay, I address the question of whether understanding the neuroscience behind human behavior should alter our legal notion of responsibility. We will examine this query in greater detail, using violence as a case study, asking whether understanding the neuroscience underlying violent behavior impacts our notion of personal or legal culpability. I shall argue that it does not. I proceed by first briefly sketching what we know about human violence and the biology behind it. Then I turn to a quick discussion of psychopaths, their connections to violence, and what we think we know about the biology of their brains. Finally, I come to the question of whether we should consider violent people with specific brain abnormalities as mad or bad, which will feed into the question of whether such people are responsible for their criminal behavior. I conclude with some very general and very brief speculations on what this discussion has to tell us about nature of being human.     

Oedipus goes to the opera: Psychoanalytic inquiry in Enescu’s Œdipe and Stravinsky’s Oedipus Rex

Abstract

Psychoanalytic inquiry into operas based on the life of Oedipus may provide further knowledge on the Oedipus complex. Therefore, we chose to analyze Enescu’s ?dipe and Stravinsky’s Oedipus Rex. Two distinct methodologies were used in our study. The first explored the concept of free association through musical themes in the operas. The second involved the comparative study of the Oedipus myth in order to provide a deeper understanding of Oedipus’s character. We observed that Oedipus displayed symptoms of his complex through the traits of aggressiveness and arrogance. Moreover, we noticed that Oedipus was compelled by the necessity of finding out who his real parents were and by unconsciously accomplishing the prophecy. Oedipus assumed the responsibility to free the Thebans from plague. Yet, it was too late, for the feared part of the prophecy was already accomplished. He provided a wrong answer to the Sphinx and then received the most severe punishment, one that would have ostracism as its outcome. It was, however, not too late for Oedipus to finally discover who his real parents were. Nevertheless, afraid of losing his place as King of Thebes, he investigated the plague’s causes. This resulted in his aggression as he resisted discovering “where babies come from.”