This chapter considers the behavioral and brain differences between separate groups of participants during long-term memory. Section 5.1 details differences between females and males (i.e., sex differences). Differences between older adults and younger adults are detailed in Section 5.2. In Section 5.3, the brains of those with superior memory are evaluated, including London taxi drivers and those who compete in World Memory Championships. Although the research on this topic is sparse, there is convergent evidence that having a superior memory does not come without a cost. Section 5.4 discusses the factors that go into determining the minimum number of participants, N, needed in each group to produce valid results that generalize to the population. All the topics of this chapter are important in that they have provided critical insights into the mechanisms mediating long-term memory, yet research on group differences (and N) is unpopular in the field of cognitive neuroscience.

This chapter focuses on the timing of brain activity associated with long-term memory. The chapter begins by introducing ERP activations that have been associated with familiarity and recollection. Familiarity has been associated with activity in frontal brain regions 300–500 milliseconds after stimulus onset, while recollection has been associated with activity in parietal brain regions 500–800 milliseconds after stimulus onset. In Section 4.2, a scientific debate that has focused on the ERP activity associated with familiarity is discussed. In Section 4.3, it is shown that synchronous activity in two different brain regions (i.e., activation time courses that increase and decrease together) indicates that these regions interact. Such synchronous activity between regions during long-term memory typically occurs within the theta frequency band, the alpha frequency band, and the gamma frequency band. Section 4.4 details some intriguing intracranial EEG findings based on recording activity in the hippocampus and the parahippocampal gyrus.

Section 1.1 gives a brief overview of the field of cognitive neuroscience. Section 1.2 details the different types of memory. In Section 1.3, an overview of human brain anatomy is provided. Commonly known anatomic distinctions such as the frontal lobe, the parietal lobe, the temporal lobe, and the occipital lobe are reviewed, and more detailed anatomy is discussed. Section 1.4 highlights the importance of the medial temporal lobe in memory, which was discovered in the 1950s when this region was surgically removed from one individual. In Section 1.5, an overview of brain sensory regions is provided, such as the regions associated with visual perception and auditory perception. In Section 1.6, the regions of the brain that control memory retrieval are considered, which include part of the frontal cortex, the parietal cortex, and the medial temporal lobe. Section 1.7 provides an overview of the organization of this book.

When Britain accepted an IMF loan in 1976 few thought that it would usher in a new political economy that would endure to the present, so how did it?

How has Britain been transformed since the financial crisis of 2008?

The techniques of celestial dynamics are useful within the solar system and other planetary systems. However, techniques that are useful in a system containing a few mutually gravitating objects are not as useful in a system containing a hundred thousand million objects.

In 1819 few Britons believed in free trade but by 1885 it had become the common sense of the nation and Britain had built an imperial system around it. How did that happen?

How did an English state torn apart by sectarian conflict, civil war and a revolution in the late seventeenth century become the most powerful in the world by 1819?

Section 6.1 considers the brain regions associated with typical forgetting, which can be attributed to a lack of attention during encoding. In Section 6.2, the brain mechanisms underlying retrieval-induced forgetting are considered, which is when retrieval of one item (e.g., the word ‘banana’) has an inhibitory effect on related items (e.g., the word ‘orange’) and increases the rate of forgetting for these items. The brain regions associated with a related process called motivated forgetting, which is an increase in the rate of forgetting for items that one intentionally tries to forget, is then considered. In the next two sections of the chapter, two types of memory distortion are considered: false memories (i.e., memories for information that did not occur) and flashbulb memories (i.e., seemingly picture-like memories for very surprising and consequential events). It has been argued that long-term memory failure reflects an adaptive memory system that works well.

Section 2.1 reviews the behavioral measures that allow for the interpretation of brain activation results. Section 2.2 discusses techniques with high spatial resolution, such as fMRI, which is the most popular method. Section 2.3 focuses on techniques with high temporal resolution, such as ERPs. ERPs measure voltages on the scalp that directly reflect the underlying brain activity. In Section 2.4, techniques with excellent spatial resolution and excellent temporal resolution are described, including combined fMRI and ERPs, as well as recording from patients with electrodes implanted in the brain for clinical reasons. Section 2.5 considers evidence from patients with brain lesions and cortical deactivation methods such as TMS. Both methods have limited spatial resolution and poor temporal resolution; however, they can assess whether a brain region is necessary for a given cognitive process. In Section 2.6, the spatial resolution and temporal resolution of the different techniques are compared.