Automatic integration of numerical formats examined with frequency-tagged EEG

How humans integrate and abstract numerical information across different formats is one of the most debated questions in human cognition. We addressed the neuronal signatures of the numerical integration using an EEG technique tagged at the frequency of visual stimulation. In an oddball design, participants were stimulated with standard sequences of numbers (< 5) depicted in single (digits, dots, number words) or mixed notation (dots—digits, number words—dots, digits—number words), presented at 10 Hz. Periodically, a deviant stimulus (> 5) was inserted at 1.25 Hz. We observed significant oddball amplitudes for all single notations, showing for the first time using this EEG technique, that the magnitude information is spontaneously and unintentionally abstracted, irrespectively of the numerical format. Significant amplitudes were also observed for digits—number words and number words—dots, but not for digits—dots, suggesting an automatic integration across some numerical formats. These results imply that direct and indirect neuro-cognitive links exist across the different numerical formats.

Neural Representation of the English Vowel Feature [High]: Evidence From /ε/ vs. /ɪ/

Many studies have observed modulation of the amplitude of the neural index mismatch negativity (MMN) related to which member of a phoneme contrast [phoneme A, phoneme B] serves as the frequent (standard) and which serves as the infrequent (deviant) stimulus (i.e., AAAB vs. BBBA) in an oddball paradigm. Explanations for this amplitude modulation range from acoustic to linguistic factors. We tested whether exchanging the role of the mid vowel /ε/ vs. high vowel /ɪ/ of English modulated MMN amplitude and whether the pattern of modulation was compatible with an underspecification account, in which the underspecified height values are [−high] and [−low]. MMN was larger for /ε/ as the deviant, but only when compared across conditions to itself as the standard. For the within-condition comparison, MMN was larger to /ɪ/ deviant minus /ε/ standard than to the reverse. A condition order effect was also observed. MMN amplitude was smaller to the deviant stimulus if it had previously served as the standard. In addition, the amplitudes of late discriminative negativity (LDN) showed similar asymmetry. LDN was larger for deviant /ε/ than deviant /ɪ/ when compared to themselves as the standard. These findings were compatible with an underspecification account, but also with other accounts, such as the Natural Referent Vowel model and a prototype model; we also suggest that non-linguistic factors need to be carefully considered as additional sources of speech processing asymmetries.

Impulse Inhibition Ability With Methamphetamine Dependents Varies at Different Abstinence Stages

Objective: The purpose of this study is to evaluate whether the impulse inhibition ability with methamphetamine dependents would vary at different abstinence stages.Methods: Sixty-three methamphetamine dependents, including 31 short-term (&lt; 10 months) and 32 long-term (≥ 10 months) abstinence participants, were recruited for this study. In addition, 33 men were recruited as the healthy control (HC) group. All participants performed a two-choice oddball task, which is well-established to assess impulse inhibition. Accuracy for deviant trials and deviant–standard reaction time (RT) delay were computed as indexes of impulse inhibition.Results: The accuracy for deviant trials was significantly decreased in short-term abstinence subjects (90.61%) compared to HC subjects (95.42%, p &lt; 0.01), which was coupled with a shorter RT delay reflecting greater impulsivity in the short-term group vs. the HC group (47 vs. 73 ms, p &lt; 0.01). However, impulse inhibition was improved in the long-term group, shown by the increased accuracy for deviant trials in the long-term group compared to the short-term group (94.28 vs. 90.61%, p &lt; 0.05) and the similar accuracy for the long-term and HC groups (p &gt; 0.05). Further regression analyses confirmed that the abstinence duration positively predicted impulse inhibition of methamphetamine dependents, both in accuracy and RT for deviant stimulus (β = 0.294, p = 0.019; β = 0.337, p = 0.007).Conclusion: These results suggest that long-term abstinence is more effective in improving impulse inhibition with methamphetamine dependents.

Weighting of Amplitude and Formant Rise Time Cues by School-Aged Children: A Mismatch Negativity Study

Purpose An important skill in the development of speech perception is to apply optimal weights to acoustic cues so that phonemic information is recovered from speech with minimum effort. Here, we investigated the development of acoustic cue weighting of amplitude rise time (ART) and formant rise time (FRT) cues in children as measured by mismatch negativity (MMN). Method Twelve adults and 36 children aged 6–12 years listened to a /ba/–/wa/ contrast in an oddball paradigm in which the standard stimulus had the ART and FRT cues of /ba/. In different blocks, the deviant stimulus had either the ART or FRT cues of /wa/. Results The results revealed that children younger than 10 years were sensitive to both ART and FRT cues whereas 10- to 12-year-old children and adults were sensitive only to FRT cues. Moreover, children younger than 10 years generated a positive mismatch response, whereas older children and adults generated MMN. Conclusion These results suggest that preattentive adultlike weighting of ART and FRT cues is attained only by 10 years of age and accompanies the change from mismatch response to the more mature MMN response. Supplemental Material https://doi.org/10.23641/asha.6207608

Time Dilation Caused by Oddball Serial Position and Pitch Deviancy

When a deviant stimulus is presented within a stream of homogeneous stimuli, its duration tends to be overestimated. Two experiments investigated the effects of oddball serial position and pitch deviancy on perceived duration. In Experiment 1, the oddball method was used, in which an oddball stimulus is embedded in a series of standard stimuli and randomly positioned in each trial. In Experiment 2, the oddball position was stable and its deviancy varied from trial to trial. Musician and nonmusician participants were asked to judge whether the comparison interval was shorter or longer than the standards. The study indicates that for nonmusicians, the duration of an oddball stimulus appears longer than the repeated standard stimuli. Moreover, the oddballs occurring in later positions in the stream of stimuli are perceived to be longer than oddballs occurring in earlier positions in the stream. Also, a higher degree of oddball deviancy results in a greater dilation of perceived duration. In contrast with the results of nonmusicians, there is neither a position nor a deviancy effect with musician participants; the subjective duration remains constant. Several explanations are discussed in order to account for these group differences.

Neuro-Behavioral Correlates of Post-Deviance Distraction in Middle-Aged and Old Adults

The presentation of a task-irrelevant deviant (novel) stimulus among otherwise repeated standard stimuli usually reduces performance not only for the deviant stimulus, but also for the standard following that deviant. Here, the so-called post-deviance distraction was investigated in 58 middle-aged and 52 old adults, using an auditory duration discrimination task and event-related potential (ERP) measures. After a deviant stimulus, the participants showed a decrease in performance in the subsequent standard stimulus. This effect was more pronounced in the old, than middle-aged, group. Relative to the standard stimuli preceding the deviant, post-deviant standards triggered a chain of mismatch negativity (MMN), P3a, and reorienting negativity (RON). While MMN and P3a did not differ in old and middle-aged adults, older participants showed a delayed RON. Assuming the RON to reflect processes of general task or feature reconfiguration and updating, these results suggest a delay in orienting-reorienting mechanisms as possible source of increased post-deviance distraction in elderly.

Electrophysiological Responses to Feedback during the Application of Abstract Rules

Much research focuses on how people acquire concrete stimulus–response associations from experience; however, few neuroscientific studies have examined how people learn about and select among abstract rules. To address this issue, we recorded ERPs as participants performed an abstract rule-learning task. In each trial, they viewed a sample number and two test numbers. Participants then chose a test number using one of three abstract mathematical rules they freely selected from: greater than the sample number, less than the sample number, or equal to the sample number. No one rule was always rewarded, but some rules were rewarded more frequently than others. To maximize their earnings, participants needed to learn which rules were rewarded most frequently. All participants learned to select the best rules for repeating and novel stimulus sets that obeyed the overall reward probabilities. Participants differed, however, in the extent to which they overgeneralized those rules to repeating stimulus sets that deviated from the overall reward probabilities. The feedback-related negativity (FRN), an ERP component thought to reflect reward prediction error, paralleled behavior. The FRN was sensitive to item-specific reward probabilities in participants who detected the deviant stimulus set, and the FRN was sensitive to overall reward probabilities in participants who did not. These results show that the FRN is sensitive to the utility of abstract rules and that the individual's representation of a task's states and actions shapes behavior as well as the FRN.