Research on the cognitive neural mechanisms of language control often overlooks the role of rewards. To investigate how reversal rewards affect bilingual language switching during observational learning, we conducted a dual-brain electroencephalography (EEG) study. Participants, classified as direct learners or observers, performed a voluntary language-switching task under dynamic reward conditions. Our results demonstrated that both direct learners and observers exhibited high correct acquisition rates for the switch and non-switch behaviors in both pre- and post-reversal phases. Notably, direct learners and observers showed reduced switch costs in the post-reversal phase, highlighting enhanced language control efficiency. EEG analyses revealed that direct learners exhibited late positive component (LPC) switch costs in both pre- and post-reversal phases, while observers showed LPC switch costs only in the post-reversal phase. These findings support the Adaptive Control Hypothesis by highlighting the adaptability of language control mechanisms in response to dynamic reward environments during direct and observational learning.

Compound words consist of two or more words which combine to form a single word or phrase that acts as one. In English, the head of compound words is usually, but not always, the right-most root (e.g., “paycheck” is a noun because the head, “check,” is a noun). The current study explores the effects of head position on language control by examining language switching performance through electroencephalography (EEG). Twenty-one pairs of Chinese (L1)–English (L2) bilinguals performed cued language switching in a simultaneous production and comprehension task. The results showed that bilinguals recognized the head position earlier both in production and comprehension. However, the language control of the head position during production occurred in the middle stage (N2), but in the late stage (LPC) during comprehension. These findings indicate that the head position in compound words exerts differential influences on language control.

When bilinguals switch between their two languages, they often alternate between words whose formation rules in one language are different from the other (e.g., a noun-verb compound in one language may be a verb-noun compound in another language). In this study, we analyze behavioral performance and electrophysiological activity to examine the effects of morphological configuration on language control during production and comprehension. Chinese–English bilinguals completed a joint naming-listening task involving cued language switching. The findings showed differential effects of morphological configuration on language production and comprehension. In production, morphological configuration was processed sequentially, suggesting that bilingual production may be a combination of sequential processing and inhibition of morphological levels and language interference. In comprehension, however, bottom-up control processes appear to mask the influence of sequential processing on language switching. Together, these findings underscore differential functionalities of language control in speaking and listening.

An enzyme of bovine retina that catalyzes oxidation of retinaldehyde to retinoic acid was purified to homogeneity and a monoclonal antibody (mAb H-4) was generated. MAb H-4 recognized a single component (Mr = 55,000) in extracts of bovine retina and other bovine tissues. The antibody showed no cross-reactivity with extracts of rat, monkey, or human retinas. A 2067 bp cDNA was selected from a retina cDNA expression library using mAb H-4. The cDNA hybridized with a similarly sized, moderately abundant mRNA prepared from bovine retina. Nucleotide sequence analysis indicated that the cDNA contained a single open reading frame encoding 501 amino acids that have 88% sequence identity with the amino-acid sequence of human hepatic Class 1 aldehyde dehydrogenase. Amino-acid sequence analysis of purified enzyme demonstrated that the cDNA encodes the isolated enzyme. MAb H-4 specifically labeled the somata and processes of a subset of amacrine cells in bovine retinal sections. Labeled amacrine somata were located on both sides of the inner plexiform layer, and their processes ramified into two laminae within the inner plexiform layer. The inner radial processes of Müller (glial) cells were weakly reactive with mAb H-4. Weak immunostaining of amacrine cells was found in monkey retina with mAb H-4, but no signal was detected in rat or human retina. The results provide further evidence for metabolism and function of retinoids within cells of the inner retina and define a novel class of retinal amacrine cells.

The atomic and electronic structures of pyramidal model STM tips of transition metals (W, Rh, Pd, Ir and Pt) were investigated using density functional theory (DFT) method. The calculated density of states show that d electrons of the apex atoms in the M4 (M = W, Rh, Pd, Ir, Pt) model tips behave differently near the Fermi level, with the dz2 state being dominant only for W tip. The electronic structures of pyramid structures of W and Pd single-atom tips with larger sizes are studied and compared. The density of states of Pd apex atom and W apex atom show different occupation of d-bands leading to asymmetric density of states for Pd tip. The asymmetric tunneling currents measured by W and Pt-Ir STM tips are explained by the calculated electronic structures of W and Pd model tips.