week 9 Flashcards
(41 cards)
What general principle allows us to understand the functions of different brain lobes?
Much of our understanding of the functions of different brain lobes comes from studying patients with brain damage. Damage to specific areas of the brain has enabled researchers to identify the function of those areas, using a method of analysis through dysfunction.
What is the primary role of the Temporal Lobe, and what syndrome is associated with its damage?
The Temporal Lobe plays a key role in auditory processing and helps with recognizing and naming objects. Damage to this region can lead to agnosia, a condition where the patient is aware of an object but cannot name it. This lobe is also crucial for identifying faces, as shown by experiments with monkeys demonstrating maximum response to complete faces and reduced response to other visual stimuli.
What are the primary functions of the Frontal Lobe, and how was its role demonstrated by Phineas Gage?
The Frontal Lobe is involved in personality, planning, social conscience, awareness, and many higher functions associated with being human. It is separated from the parietal lobe by the central sulcus, containing the primary motor cortex. The story of Phineas Gage, who survived a severe injury to his frontal lobe and underwent dramatic personality changes, underscores its importance in higher functions and personality.
Describe Contralateral Neglect Syndrome and its implications on brain symmetry.
Contralateral Neglect Syndrome occurs when a patient neglects stimuli associated with the left side of an image they are asked to copy, indicating an unawareness of the difference from the model. This syndrome, typically not seen with left-sided parietal damage, highlights that brain functions are not symmetrical across the cortex
How do the brain’s hemispheres differ in function?
The brain’s hemispheres show asymmetry in function. For example, reasoning, linguistic analysis, and numerical analysis are typically associated with one hemisphere, while spatial perception and artistic tasks are mapped to the other. This suggests that not all functions are symmetrically distributed across the brain.
What is the role of the Occipital Lobe, and what unique condition can arise from its damage?
The Occipital Lobe receives and processes visual information, playing a critical role in creating binocular vision, detail, and depth perception. Damage to this lobe can lead to unique conditions such as the loss of motion perception, where a patient might see waterfalls as static images or cars approaching as a series of still images.
What advancements have aided our understanding of the brain’s specific areas and their functions?
Studies of brain-damaged patients have been pivotal in mapping specific brain areas to their functions. Additionally, advancements in imaging technologies such as PET, MRI, and fMRI have furthered our understanding by allowing the observation of active brain areas and their roles in processing.
How is language processed in the brain, and what are the effects of damage to specific areas?
Language processing involves detecting words by the auditory cortex, processing by Wernicke’s area, transmission to Broca’s area, and then stimulating the motor cortex for speech. Damage to Wernicke’s area results in receptive aphasia (inability to understand or produce meaningful speech), while damage to Broca’s area leads to expressive aphasia (ability to understand but difficulty in producing speech).
Discuss the complexity of the brain’s processing of visual stimuli beyond the visual cortex.
The visual system detects size, color, shape, and motion, but the brain’s processing of visual stimuli is multi-dimensional, involving other senses, memory, motor responses, and emotions. This complex processing ensures a comprehensive response to visual stimuli, indicating the involvement of multiple brain areas beyond just the visual cortex.
What is the goal of the Blue Brain Project, and what progress has been made?
The Blue Brain Project, run by IBM and funded by the Pentagon and Swiss government, aims to create a synthetic mammalian brain, with the goal of a functional, speaking, thinking brain within 10 years. Progress includes modeling a column of rat neurons (containing 10,000 neurons and 108 synapses) and the need for significant computational power to simulate connections, with future steps focusing on developing a more biological model
What are the two main components of the vertebrate nervous system?
The vertebrate nervous system is divided into the Central Nervous System (CNS) and the Peripheral Nervous System (PNS). The CNS, responsible for storage and processing, comprises the brain and spinal cord, while the PNS connects the CNS to the rest of the body, with its complexity varying among vertebrates.
What are the functions of the brain stem, cerebellum, and cerebrum?
The brain stem controls basic, autonomic functions. The cerebellum integrates sensory and motor movements for precision. The cerebrum is involved in complex behavior, emotions, learning, and memory.
Describe the complexity and main focus of the shark brain.
The shark brain is very simple, primarily focused on autonomic functions, sensory input, and motor response. It has little or no cerebellum or cerebrum, reflecting the shark’s simple behaviors of eating and swimming.
How does the alligator brain differ from the shark brain?
The alligator brain is slightly more complex, with a more developed brain stem and olfactory bulb, plus a cerebellum for complex motor responses like the death roll. It shows little or no cerebrum, indicating a focus on sensory activity and motor responses in and out of water.
What characteristics define the pig brain?
The pig brain is complex, reflecting the animal’s social awareness, personality, and memory capabilities. It has a highly developed sense of smell, superior to humans, and co-ordinated motor and sensory systems, thanks to a developed cerebrum and cerebellum.
What features make the human brain distinct?
The human brain is highly complex, with the cerebrum being the most prominent area. It’s associated with complex behavior, social awareness, consciousness, advanced learning and memory, and a complex personality structure.
Describe the human nervous system at 25 days of development.
At 25 days, the human nervous system is characterized by the formation of the neural tube, a hollow tube of tissue that runs along the dorsal surface of the early embryo. This structure is the precursor to the central nervous system (CNS) and shows initial swellings that will fold and develop into the main divisions of the CNS, namely the forebrain, midbrain, and hindbrain.
What are the significant developments in the human nervous system at 40 days?
By 40 days, the forebrain differentiates into two parts: the telencephalon, which will become the cerebrum, and the diencephalon, which serves as a relay site within the forebrain. The structures begin to show more convolution, with the neural tube’s divisions still maintained and the regions remaining in the same linear order. Developing eyes are also visible at this stage.
What key structures have developed in the human nervous system by 100 days?
At 100 days, the cerebrum and cerebellum are more pronounced, with the cerebellum providing intricate control of motor and sensory function. The hindbrain, consisting of the pons and medulla (brain stem), connects the spinal cord to the brain and manages involuntary functions like breathing and circulation. The midbrain, also part of the brain stem, is involved in processing sensory inputs, especially vision and olfaction
What are the features of the evolved human brain and its sensory integration?
The human brain has an advanced cerebellum, allowing for a high degree of integration and the capacity for precise, fine motor movements and skills. The olfactory lobe is comparatively underdeveloped, indicating a greater reliance on other sensory systems. Integration between sensory inputs makes up for individual senses that are less evolved, creating a multi-dimensional sensory experience where a single stimulus can activate multiple senses at the same time.
What distinguishes the human brain in terms of cerebellar development and sensory processing?
The human brain has a highly evolved cerebellum, facilitating an extensive amount of neural integration. This enables precise and fine motor movements and skills. Although the olfactory lobe is comparatively underdeveloped, the human brain compensates with a greater reliance on other, more advanced sensory systems. There is a significant degree of integration, or ‘cross-talk’, between these sensory inputs, which enhances the complexity of sensory experiences. This integration results in a level of sensation that is greater than the sum of its individual sensory components, making human sensory experiences multi-dimensional. As a result, a single sensory stimulus can simultaneously activate multiple sensory systems.
What are the structures and functions of the telencephalon and diencephalon in the forebrain?
The telencephalon is the cerebrum, divided into two hemispheres, consisting of a complex array of lobes responsible for perception, learning, memory, and conscious behavior. The diencephalon, also known as the ‘in-between brain,’ includes the thalamus, which is the final sensory relay between the spinal cord and forebrain, and the hypothalamus, which regulates many functions like temperature, thirst, and hunger.
How has the forebrain evolved in vertebrates, and what is telencephalization?
The forebrain, particularly the cerebrum, has become increasingly dominant through the evolution of more complex organisms, a process known as ‘telencephalization.’ In mammals and humans, the cerebrum plays a crucial role, with damage leading to profound implications. Conversely, in fish, the removal of the cerebrum results in little or no effect, highlighting the cerebrum’s relatively lesser importance in less complex organisms.
Describe the division of the telencephalon and the role of the corpus callosum.
The telencephalon is divided into two halves, known as the cerebral hemispheres. These hemispheres communicate with each other via the corpus callosum, a thick band of nerve fibers that contains 200-250 million axonal projections. This structure enables the two sides of the brain to communicate and work together effectively.
