Explain how infant intelligence is measured using information-processing approaches.

To understand how children, particularly infants, process information, we turn to information-processing approaches.

These approaches compare the brain to a computer, considering how information is taken in (input), manipulated, and stored in the brain (processing), and later used to make decisions or solve problems (output).

In infants, these processes can be quite subtle but they're vital in gauging how they understand and interact with the world around them. This includes how they pay attention to, remember, and perceive different stimuli. The efficiency and strategies that children use in processing information can be key indicators of cognitive development and intelligence.

Habituation studies in infants involve presenting a baby with a certain stimulus repeatedly until their interest wanes and a decreased response is observed – this is known as habituation.

When a new stimulus is introduced and the baby's interest peaks again, this is called dishabituation. These studies measure the speed and extent of these responses.

A faster habituation rate can indicate that the infant is processing and understanding the initial stimulus more quickly, while a clear dishabituation suggests that the infant can discriminate between old and new information. These responses reflect underlying cognitive processes such as learning, memory, and attention, giving insights into the infant's intellectual development.

Visual preference methods leverage an infant's natural curiosity about their environment. Researchers show infants two images or objects simultaneously to see which one they look at longer.

Preference for new, complex, or patterned stimuli can suggest that the infant is engaged in more sophisticated information processing.

This method helps to uncover cognitive abilities related to visual processing and attention. It may reveal an infant's ability to differentiate between stimuli and to potentially store visual information, aspects closely tied to intellectual engagement and development.

Cross-modal transfer techniques assess an infant's ability to integrate information across different sensory modalities – such as sight, touch, and hearing.

For instance, an infant may be allowed to explore an object by touch and later recognize that same object by sight alone. The ability to recognize and relate information learned from one sense to another indicates high levels of cognitive processing and suggests advanced intellectual capabilities.

This kind of sensory integration is crucial for understanding the physical world and for developing problem-solving skills. It demonstrates an early form of reasoning – a cornerstone in intelligence measurement.