William S. Hall

Organization of the avian basal forebrain: Chemical anatomy in the parrot (Melopsittacus undulatus)

Hodological, electrophysiological, and ablation studies indicate a role for the basal forebrain in telencephalic vocal control; however, to date the organization of the basal forebrain has not been extensively studied in any nonmammal or nonhuman vocal learning species. To this end the chemical anatomy of the avian basal forebrain was investigated in a vocal learning parrot, the budgerigar (Melopsittacus undulatus). Immunological and histological stains, including choline acetyltransferase, acetylcholinesterase, tyrosine hydroxylase, dopamine and cAMP‐regulated phosphoprotein (DARPP)‐32, the calcium binding proteins calbindin D‐28k and parvalbumin, calcitonin gene‐related peptide, iron, substance P, methionine enkephalin, nicotinamide adenine dinucleotide phosphotase diaphorase, and arginine vasotocin were used in the present study. We conclude that the ventral paleostriatum (cf. Kitt and Brauth [ 1981 ] Neuroscience 6:1551–1566) and adjacent archistriatal regions can be subdivided into several distinct subareas that are chemically comparable to mammalian basal forebrain structures. The nucleus accumbens is histochemically separable into core and shell regions. The nucleus taeniae (TN) is theorized to be homologous to the medial amygdaloid nucleus. The archistriatum pars ventrolateralis (Avl; comparable to the pigeon archistriatum pars dorsalis) is theorized to be a possible homologue of the central amygdaloid nucleus. The TN and Avl are histochemically continuous with the medial aspects of the bed nucleus of the stria terminalis and the ventromedial striatum, forming an avian analogue of the extended amygdala. The apparent counterpart in budgerigars of the mammalian nucleus basalis of Meynert consists of a field of cholinergic neurons spanning the basal forebrain. The budgerigar septal region is theorized to be homologous as a field to the mammalian septum. Our results are discussed with regard to both the evolution of the basal forebrain and its role in vocal learning processes. J. Comp. Neurol. 454:383–408, 2002.

Contextual constraints on usage of cognitive words

The conversations of 36 41/2 to 5-year-olds differing in race (black and white) and social class (professional and working class) and the adults with whom they spoke were tape-recorded during play and teaching time at preschool and dinnertime at home. Usage of cognitive words was analyzed for six levels of meaning that differed in depth of processing from reference to (1) perception and attention, (2) recognition, (3) fact recall, (4) understanding, (5) metacognition, and (6) evaluation of presuppositions. Although the rank order of usage was the same, children devoted less of their lexicon to the three higher levels of meaning than adults. Even in adults, perceptual references predominated. Use of higher-level meaning was less prominent in school and in the black working-class population. There were significant correlations between exposure to adult conversations with high-level meaning and child use of those meanings, and between the diversity of cognitive vocabulary in children and adults, but those correlations were smallest in the black working-class population.

Acquisition of the Mental State Verb Know by 2- to 5-Year-Old Children

The production of the cognitive internal state word know by four 2- to 5-year-old children and their parents was examined. The levels of meaning of cognitive words can be categorized hierarchically along the dimensions of conceptual difficulty and abstractness (see Booth & Hall, 1995). The present study found that children and their parents expressed low levels of meaning less frequently, whereas they expressed high levels of meaning more frequently as a function of age. The childrens use of know was also correlated positively with (1) their number of different words produced suggesting that cognitive words are related to more general semantic processes, and (2) with parental use of those same cognitive words suggesting that parental linguistic input may be an important mechanism in cognitive word acquisition. Finally, young children tended to use know more to refer to themselves than to refer to others, whereas their parents tended to use know equally to refer to self and others. The importance of cognitive words in a theory of language acquisition is discussed.

Functional anatomy of forebrain vocal control pathways in the budgerigar (Melopsittacus undulatus)

Budgerigars throughout life are capable of learning to produce many different sounds including those of human speech. Like humans, budgerigars use multiple craniomotor systems and coordinate both orosensory and auditory feedback in specialized forebrain nuclei. Although budgerigar auditory-vocal learning has a different evolutionary origin from that of human speech, both the human and budgerigar systems can control F0 and can alter the distribution of energy in spectral bands by adjusting the filter properties of the vocal tract. This allows budgerigars to produce an extremely diverse array of calls including many broadband and highly complex sounds.

Development of the understanding of the polysemous meanings of the mental-state verb know

Abstract This study investigated childrens understanding (3-, 6-, 9-, and 12-year-olds) of the different levels of meaning of the cognitive verb know as defined by the Hall, Scholnick, and Hughes (1987) abstractness and conceptual difficulty hierarchy. We found that cognitive verb knowledge increased with development and that certain low levels of meaning were mastered before certain high levels of meaning irrespective of the medium of presentation: video-taped “skits” and audio-taped “stories.” However, children developed an understanding of low levels of meaning at a more rapid rate than high levels of meaning. This resulted in a more differentiated and hierarchical cognitiveverb knowledge in older children. Finally, we found that the audio-taped stories were more difficult than the video-taped skits, and that both tasks were significantly correlated with a standardized vocabulary measure for all ages except the 3-year-olds. The implications of this study and others for a model of the cognitive-verb lexicon are discussed.

DISTRIBUTION OF CHOLINE ACETYLTRANSFERASE AND ACETYLCHOLINESTERASE IN VOCAL CONTROL NUCLEI OF THE BUDGERIGAR (MELOPSITTACUS UNDULATUS)

The present study used histochemical methods to map the distributions of choline acetyl transferase (ChAT) and acetylcholinesterase (AChE) in the vocal control nuclei of a psittacine, the budgerigar (Melopsittacus undulatus). The distributions of ChAT and AChE in budgerigars appeared similar to that in oscine songbirds despite evidence that these systems have evolved independently. The magnicellular nucleus of the lobus parolfactorius in budgerigars, like the area X in songbirds, contained many ChAT labeled somata, fibers, and varicosities and stained densely for AChE. In contrast, the robust nucleus of the archistriatum (RA) and the supralaminar area of the frontal neostriatum in budgerigars, like the RA and the magnicellular nucleus of the neostriatum (MAN) in songbirds, respectively, contained few or no ChAT labeled somata, fibers, and varicosities and stained lightly for AChE. The central nucleus of the lateral neostriatum in budgerigars, like the higher vocal center (HVC) in songbirds, contained no ChAT labeled somata, moderate densities of ChAT labeled fibers and varicosities, and moderate levels of AChE staining. Two nuclei, the oval nucleus of the hyperstriatum ventrale (HVo) and the oval nucleus of the anterior neostriatum (NAo), contained no ChAT labeled somata, dense ChAT labeled fibers and varicosities, and moderate to high levels of AChE staining. The HVo and the NAo have no counterparts in songbirds but may be important vocal control nuclei in the budgerigar. Cholinergic enzymes are also described in other regions which may be involved in budgerigar vocal behavior, including the basal forebrain, the torus semicircularis, and the hypoglossal nuclei (nXII).

Distribution of tyrosine hydroxylase-containing neurons and fibers in the brain of the budgerigar (Melopsittacus undulatus): general patterns and labeling in vocal control nuclei.

The distribution of tyrosine hydroxylase (TH) was mapped out in cells and fibers of the budgerigar (Melopsittacus undulatus) brain. Special attention was given to vocal control and auditory nuclei because budgerigars are a psittacine species in which both males and females are capable of lifelong vocal learning (Farabaugh et al. [1994] J. Comp. Psychol 108:81–92). The results show that TH staining in the central nucleus of the anterior archistriatum (AAc) resembled that of surrounding archistriatal fields, except for portions of the ventral archistriatum, which exhibited substantially more TH+ fibers. Fewer fibers and fiber baskets are present in the central nucleus of the lateral neostriatum (NLc) than in surrounding fields. Both the oval nuclei of the ventral hyperstriatum (HVo) and anterior neostriatum (NAo) exhibit less fiber staining than surrounding fields whereas fiber staining in the medial NAo (NAom) and magnicellular nucleus of the parolfactory lobe (LPOm) resemble that of surrounding fields. Staining in primary telencephalic auditory nuclei was extremely low. The only sex difference observed was slightly increased TH staining in LPOm of females compared with surrounding fields on some tissue sections. These findings are in contrast to previous findings in zebra finch (Poephila guttata), a close ended vocal learning songbird in which TH staining in vocal nuclei increases during development and remains greater than surrounding fields throughout adulthood. The present results therefore support the view that catecholamines act to inhibit vocal plasticity in adult vocal learning species. Several unique features of TH‐immunoreactive (ir) cell groups were observed in the brainstem including sparsely scattered TH‐ir somata immediately adjacent to the third ventricle, within the tectum, basal forebrain, archistriatum, and caudal neostriatum, and in the hippocampus. These latter populations have not been described in other avian species and resemble features of the catecholamine system generally found in either reptiles or mammals. J. Comp. Neurol. 429:436–454, 2001.

Polysemy and the acquisition of the cognitive internal state lexicon

Previous research (Hall, Scholnick, & Hughes, 1987) suggested that cognitive word meanings denote six increasingly abstract and complex cognitive processes. In this paper, we further investigated two interrelated aspects of this framework. A set of 36 conversations with children aged 4:5 to 5 provided the data. In Study 1, issues related to the optimal ordering of levels were examined by comparing the original sequence with a restructured model. In Study 2, the hypothesis that, in addition toknow, other polysemous cognitive internal state words would be hierarchically organized was tested. The findings lent support to the restructured model, but rejected the hypothesis that polysemous words within the domain were characterized by equivalent,hhierarchically organized levels. We conclude by proposing that cognitive internal state words were related by complementarity of levels rather than equivalence.

Cytoarchitecture of Vocal Control Nuclei in Nestling Budgerigars: Relationships to Call Development

Changes in the cytoarchitecture of vocal control nuclei were investigated in nestling budgerigars (Melopsittacus undulatus) from hatching to fledging (five to six weeks) in relation to changes in vocalizations produced by nestlings during this period. The nuclei investigated were the hypoglossal nucleus, dorsomedial nucleus of the intercollicular midbrain, central nucleus of the archistriatum, central nucleus of the lateral neostriatum, oval nucleus of the hyperstriatum ventrale, medial division of the oval nucleus of the anterior neostriatum, and magnocellular nucleus of the lobus parolfactorius. These nuclei have been shown to form functional circuits in adults related to vocal learning. Consistent with previously reported results, we found that call development could be described in terms of five different phases based on changes in the duration and segmentation of single and multiple segment foodbegging calls and the appearance of the first socially learned contact calls around the time of fledging. We also found that call segment duration exhibited an inverted U-shaped developmental function during the nestling period, as has been found for total call duration. Cytoarchitectonic studies revealed striking changes in the cellular architecture of vocal control nuclei during the first four weeks posthatching. At hatching the hypoglossal nucleus exhibits adult-like cytoarchitecture, and the central nucleus of the archistriatum and the central nucleus of the lateral neostriatum are distinguishable from surrounding fields. By one week posthatch, the central nucleus of the archistriatum exhibits an adult-like appearance, while other telencephalic vocal control nuclei do not exhibit adult-like cytoarchitecture until three to four weeks posthatching. By two weeks posthatching, the dorsomedial nucleus of the intercollicular midbrain also exhibits adult-like cytoarchitecture. We observed substantial decreases in the thickness of ventricular proliferation zones during this period, with decreases in ventricular zones occurring at about the same point that nuclei at corresponding levels come to exhibit adult-like cytoarchitectonic features. Of interest is the fact that cytoarchitectural development occurs asynchronously in different brain regions, with the appearance of adult-like characteristics in the hindbrain and midbrain occurring before the appearance of adult-like cytoarchitectonic characteristics in telencephalic nuclei. These results are consistent with recent lesion studies indicating that neither auditory feedback nor telencephalic vocal control nuclei are necessary for the production of foodbegging and other nestling calls until three to four weeks posthatching.

The Semantic-Pragmatic Distinction in the Investigation of Mental State Words: The Role of the Situation.

The semantic uses of mental state words used by children 4½ to 5 years of age were compared. The children were from two racial (black and white) and two social class (working and professional) groups. The sample of language was collected in 10 different temporal situations which were subsumed under two broad categories of situation (home or school). The total corpus of language consisted of one million words. A racial difference in the use of mental state words was found in the school situation. The situation specificity of this finding suggests the potency of the situation and not any general difference in familiarity with mental state words. How children make use of their linguistic and cognitive capacities can be influenced substantially by subtle situational factors. The effects of such situational factors can vary substantially depending on the cultural background of the children.